Solve the equations below. Give exact solutions only. Show your work.

a) 5x^2 - 7 = 72
b) x(x + 2) = 5
c) 3x^2 + 2x - 4 = 0

Please help!

Answers

Answer 1

Step-by-step explanation:

remember, the general formula to solve a quadratic equation ax² + bx + c = 0 is

x = (-b ± sqrt(b² - 4ac))/(2a)

a)

I think there is a typo, and this should be

5x² - 7x = 72

5x² -7x - 72 = 0

x = (7 ± sqrt(49 - -1440))/10 = (7 ± sqrt(1489))/10

x1 = (7 + sqrt(1489))/10

x2 = (7 - sqrt(1489))/10

b)

x(x + 2) = 5

x² + 2x - 5 = 0

x = (-2 ± sqrt(4 - -20))/2 = (-2 ± sqrt(24))/2 =

= (-2 ± sqrt(4×6))/2 = (-2 ± 2×sqrt(6))/2 =

= -1 ± sqrt(6)

x1 = -1 + sqrt(6)

x2 = -1 - sqrt(6)

c)

3x² + 2x - 4 = 0

x = (-2 ± sqrt(4 - -48))/6 = (-2 ± sqrt(52))/6 =

= (-2 ± sqrt(4×13))/6 = (-2 ± 2×sqrt(13))/6 =

= (-1 ± sqrt(13))/3

x1 = (-1 + sqrt(13))/3

x2 = (-1 - sqrt(13))/3


Related Questions

A community hall is in the shape of a cuboid.
The hall is 20m long, 15m wide, and 4m high.

Answers

Answer:

The total paint cost is £380. The total tiles cost is £1800. The total cost is £2180.

Step-by-step explanation:

To know the cost, you need to calculate the area of the community hall.

Area of the ceiling/floor: 40m x 15m =  600m2

So together, their area is 1200m2.

Area of the small walls of the community hall: 15m x 3m = 45m2/each wall

Together the two walls have an area of 90m2

Area of the big walls of the community hall: 40m x 3m = 120m

Together the two big walls have an area of 240m2

So, therefore, the total area of the community hall: 1530m2

Painting:

They are going to paint the walls and the ceiling and each 10L tin covers 25m2 so:

Area of the walls and ceiling = 600m2 + 90m2 + 240m2 = 930m2

930m2 ÷ 25m2 = 37.5 tins. Since you can't have half a tin, they will need 38 10L tins.

38 x £10 = £380

Floor:

1m2 floor tiles costs £3 so 600m2 x £3 = £1800

Total:

£1800 + £380 = £2180

What is the distance between -9and -2 on the number line

Answers

Answer:

7 units

Step-by-step explanation:

Calculate the distance using the absolute value function

| - 9 - (- 2) | = | - 9 + 2 | = | - 7 | = 7

or

| - 2 - (- 9) | = | - 2 + 9 | = | 7 | = 7

The distance between -9 and -2 on the number line is -7.

May I please receive help?

Answers

Are you looking for a acute angle?

Answer:

Its right angel

Step-by-step explanation:

Sorry if m wrong


A stainless steel gas grill is list priced at $495. The manufacturer offers a series discount of 25/20/10 to wholesalers and a 25/20 series discount to
retailers. What is the difference between the prices?

Answers

Answer:200$

Step-by-step explanation:

Find the m, b, and write the equation for the following graph:

Answers

Answer:

y = 3, m=0, b=3

Step-by-step explanation:

Hi there! If you look at the graph, we have a horizontal like crossing through y=3. your m value will be 0 as there is no slope. For your b value, it will be 3 as the y-intercept is 3.

I hope this helps!

Is the relationship between the temperature scales proportional?Why or why not?

Answers

Answer: No, see explanation below

Step-by-step explanation:

For the relationship between the temperature scales to be proportional, the ratio (the number we get when dividing the given temperature in Celsius by the temperature in Fahrenheit) has to be constant.

[tex]\frac{0}{32}=0\\\frac{10}{50}=0.2\\\frac{20}{68}=0.29[/tex]

In the example, I give, we can see that is not the case. It applies to any value as well, therefore the relationship between the temperature scales is NOT proportional

Does any one mind helping me on this question I have struggle solving it

Answers

answer for (a) attached.

PLEASE ANSWER QUICKLY 100 POINTS!!!! Simplify the expression below. (See picture below) What is the numerator of the simplified expression?

Answers

Answer:

13N+26/9n-26/3

Step-by-step explanation:

Answer:

13N+26/9n-26/3

Step-by-step explanation:

Mark as brainliest

HELP HELP ME PLS I AM RUNNING OUT OF TIME!!!! HERE IS MY PROBLEM:
An attorney drove 9 1/4 miles from his home to a clients home and another 4 3/5 miles to get to his office. How far did he drive in total?​

Answers

Answer:

Step-by-step explanation:

To write fractions with a common denominator, you will most likely need to scale some numbers up! I will explain how.

Let's try it with the fractions

2

3

and

3

12

12 is larger than 3, so we will have to multiply the 3 by some number to equal 12. (We are really finding the Least Common Multiple of the two denominators!) To do this, you have to multiply the 3 by 4, because 3x4=12. But now the numerator doesn't match the denominator. When you scale the denominator up, you have to scale the numerator up too! So the 2 must be multiplied by 4 also.

Now you have the following:

8

12

and

3

12

These fractions now have common denominators! Now they're all set for adding or subtracting fractions.

Try another:

2

6

and

3

5

: The least common multiple of 6 and 5 is 30. (the product of the denominators)

Transform each fraction by multiplying by "1":

2

6

5

5

=

10

30

and

3

5

6

6

=

18

30

One last problem:

4

9

and

7

6

What is the least common multiple of 9 and 6? Could you use 54? Absolutely, but it is not the LEAST number that you could use. How about 18? YES!

4

9

2

2

=

8

18

and

7

6

3

3

=

21

18

Ready to go...

Hope this helped!

Giving brainliest
Write the inequality that represents the possible values for x

Answers

Answer:

6x +12 < 10

Step-by-step explanation:

anybody help please hehehe​

Answers

Answer:

It is the second one 20^247

Step-by-step explanation:

A bicycle has a listed price of $588.95 before tax. If the sales tax rate is 8.25% , find the total cost of the bicycle with sales tax included. Round your answer to the nearest cent, as necessary.

Answers

Answer:

$637.54

Step-by-step explanation:

The cost is $588.95 and the tax is 8.25%, which needs to be turned into a decimal by moving the decimal 2 places to the left. .0825. Now multiply 588.95 x .0825 and that gives you the tax: $48.59 after rounding. Now add the tax to the price: 588.95 + 48.59 = $637.54.

а 5. Protein Bar A has 15 grams of protein in
a 40 gram bar. Protein Bar B has 20 grams of protein in a 60 gram bar. Which bar has more protein per gram?​

Answers

The answer is Protein Bar A

Calculate the area of trapezium CDEF.

Answers

Answer:

i think 24 cm² is answer good luck

What is an equation of the line that passes through the points (4, -1) and (-8, -7)?

Answers

Answer:

y=-1/2x - 3

I think this is it, its been a while though.

The perimeter of the figure below is 140 ft.
Find the length of the missing side.

Answers

Answer:

9.2 ft

Step-by-step explanation:

140 - 9.6 - 10.2*8 - 19.8*2 = 9.2

mark me as brainliest PLEASE

Please help I need help by the end of today

Answers

Answer:

  A.  x = 7, y = 3

Step-by-step explanation:

The triangles are congruent by HL if the hypotenuses are congruent, and if the marked legs are congruent.

  3x -1 = 6y +2 . . . . hypotenuses are congruent

  2x = 5y -1 . . . . . . .legs are congruent

Subtracting 2 times the first equation from 3 times the second gives ...

  3(2x) -2(3x -1) = 3(5y -1) -2(6y +2)

  6x -6x +2 = 15y -3 -12y -4

  9 = 3y . . . . . . . . . . . add 7 and simplify

  y = 3 . . . . . . . . divide by 3

This value of y matches only answer choice A.

pls help!! the answers are written but can someone explain how to find the angles step by step? I already know how to find the hypotenuse length.

Answers

There are a few options we can take. One way is to use the tangent ratio to tie together the opposite and adjacent sides, and then apply the inverse tangent (aka arctangent) to get the angle itself.

Let x be the upper left acute angle, and y be the lower right acute angle.

We can say

tan(angle) = opposite/adjacent

tan(x) = 16/5

x = arctan(16/5)

x = 72.645975 approximately

x = 72.6

and also

tan(angle) = opposite/adjacent

tan(y) = 5/16

y = arctan(5/16)

y = 17.3540246

y = 17.4

Note how x+y = 72.6+17.4 = 90. The two acute angles of any right triangle are complementary, meaning they always add to 90. So if you found x, then you can compute y = 90-x without needing the tangent ratio.

Your calculator needs to be in degree mode when using the arctangent function, which is denoted as [tex]\tan^{-1}[/tex] on many graphing calculators.

Can you help me please

Answers

I think it’s 32? i dont know good luck

Can someone please help me with this one? Tysm!!

Answers

Answer:

-26

Step-by-step explanation:

well add the negative numbers first so you get

-17-18=(-35)

then you add 9 so its (-35)+9=26

Answer:

Step-by-step explanation:

-17 + 9 +(-18) = -8 -18 = -26 final answer

Monty Ricker obtained a used car loan of $6,000.00 at 8% for 36 months. The monthly payment is $ 187.80. The balance of the loan after 12 payments is $ 4,159.90. The balance after the 34th payment is $ 380.60.

Answers

Answer:

What is the intrest for the 13th payment?

Answer:  What is the interset

Step-by-step explanation:

At the Coyotes' football game yesterday, the Coyotes scored 6 points for every 1 point scored by their opponent, the Rams. Pick the diagram that models the ratio in the story. If the Coyotes scored 42 points, how many points did the Rams score

Answers

Answer:

The Rams scored 7 points.

Step-by-step explanation:

42/6 = 7

since the Coyotes scored 42 points, you would divide that score by however many they would get for every 1 point the Rams would get.

A company pays its employees $26 for every 4 hours of overtime worked in a day.

Mike works 9 hours of overtime and is paid $53.
Rachael works 8 hours of overtime and is paid $52.
Tom works 17 hours of overtime and is paid $442.
John works 16 hours of overtime and is paid $100.


Which employee receives an appropriate payment for the hours of overtime worked, according to the given unit ratio?

Answers

Answer:

John

Step-by-step explanation:

expand: -4(2x + 2) +3​

Answers

Answer:

-8x-8+3

-8x-5

that is the answer for this question and I will send you the link to mp3 and

guys please (number 3)

Answers

Answer:

500 < c < 1,700

Step-by-step explanation:

Please help me

if v=6, w=-9, and x=7

Answers

Answer:

im sorry but r u even trying..... bc i just answer one of ur questions

Step-by-step explanation:

-19

(-9)^2 = 81
3(6) + (7) = 25
(-9) + (6-1) = -4

Now solve. 81-5= 76
76\ -4 = -19

What is the percent of decrease from 100 to 38?

Answers

Answer: 62

Step-by-step explanation:

100 - x = 38

x =62

Danielle pays $35 for 6 1/3 pounds of coffee.Charyn pays $60 for 9 1/4 of coffee. Whose coffee cost more per pound . What is the difference per pound in the coffee

Answers

Answer:

Charyn's coffee is the dearest.

Difference per pound is $0.96.

Step-by-step explanation:

Price per pound = total price / pounds bought

For Danielle this

is  35 / 6 1/3

= 35 / 19/3

= 35 * 3 / 19

= $5.526.

For Charyn  this

is  60 / 9 1/4

= 60 / 37/4

= 60 * 4 / 37

= $6.486.

Difference = $0.96.

Rationalize the denominator 1/ (5-2√3)​

Answers

Explanation :-

At first, we have to multiply the numerator and the denominator and the denominator's inverse such that (a-b)(a+b) = a² - b² is formed in the denominator.

Denominator = 5-2√3Rationalizing factor = 5 + 2√3

[tex]\qquad[/tex]_________________________

[tex]\bf Multiplying\:by\:\: \purple{ \dfrac{5+\sqrt{3}}{5+\sqrt{3}}}\\[/tex]

[tex]\qquad[/tex][tex] \longrightarrow \bf \dfrac{1}{5 - 2\sqrt{3} } \times \dfrac{5 + 2\sqrt{3} }{5 + 2\sqrt{3} }\\ [/tex]

[tex]\qquad[/tex][tex]\longrightarrow \sf \dfrac{1(5 + 2\sqrt{3}) }{(5 - 2\sqrt{3})(5 + 2\sqrt{3}) } [/tex]

[tex]\qquad[/tex][tex]\longrightarrow \sf \dfrac{5 + 2\sqrt{3} }{ {(5)}^{2} - (2 \sqrt{3})^{2} } [/tex]

[tex]\qquad[/tex][tex] \longrightarrow \sf \dfrac{5 + 2 \sqrt{3} }{(5 \times 5) - (2 \times 2 \times \sqrt{3} \times \sqrt{3} )} [/tex]

[tex]\qquad[/tex][tex] \longrightarrow \sf \dfrac{5 + 2 \sqrt{3} }{(25) - (12)} [/tex]

[tex]\qquad[/tex][tex] \purple{ \longrightarrow \bf \dfrac{5 + 2 \sqrt{3} }{13} } [/tex]

[tex]\qquad[/tex]_________________________

Answer is 2/(5+√13)

Rationalize the denominator 1/ (5-2√3)

If two terms of an arithmetic sequence are a11 = 23 and a15 = −5, what is a28?

Answers

The value of a28 given a11 = 23 and a15 = −5 is -96

Given:

a11 = 23

a15 = −5

Where,

a1 = first term

d = common difference

a11 = a + 10d = 23

a15 = a + 14d = -5

a + 10d = 23 (1)

a + 10d = 23 (1)a + 14d = -5 (2)

subtract (1) from (2) to eliminate a

14d - 10d = -5 - 23

4d = -28

d = -28 / 4

d = -7

Substitute d = -7 into (1)

a + 10d = 23 (1)

a + 10(-7) = 23

a - 70 = 23

a = 23 + 70

a = 93

So,

a28 = a + 27d

= 93 + 27(-7)

= 93 + -189

= 93 - 189

= -96

Therefore, the value of a28 given a11 = 23 and a15 = −5 is -96

Learn more about arithmetic sequence:

https://brainly.com/question/6561461

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