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2 years ago

please give me the steps to solve this, will mark brainlyest if leads to correct answer

Mathematics

1 answer:

ZanzabumX [31]2 years ago

3 0

Answer: The car will skid 200 miles

Step-by-step explanation:

The formula S= 7/2√2D

can be used to approximate the speed S, in miles per hour, of a car that has left skid marks of length D, in feet. To determine how far a car will skid at 70 mph, we will substitute 70 mph for S in the formula. It becomes

70 = 7/2√2D

We will take squares of both sides. This is to simplify the square root on the right had side of the equation. It becomes

70^2 = 7^2/2^2(√2D)^2

4900 = 49/4 × 2D

4900 = 49D/2

Cross multiplying,

49D = 2 × 4900 = 9800

D = 9800/49 = 200

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Pythagorean theorem

marta [7]

Answer:

x = 8

Step-by-step explanation:

$a^{2} +b^{2} =c^{2} \\$ so $8^{2} +b^{2} =\sqrt{80} ^{2}$

rearrange the formula:

$\sqrt{80} ^{2} - 8^{2} = b^{2}$

$80 - 64 = b^2$

$b^2 = 16\\$ $b = \sqrt{16}$

$\sqrt{16} = 4$

$x = 4+4 = 8$

7 0

2 years ago

Solve the following equation for x 5(x - 1) = -45

abruzzese [7]

Answer:

solution: x = -8

Step by step:

1) 5x-5+5 = -45+5 : Add 5 to both sides

2) 5x= -40 : Simplify

3) 5x/5 = -40/5 : Divide both sides

Hope that helps

5 0

2 years ago

9x^3y^6/xy^6 Solve using only positive exponents

DedPeter [7]

Look at the attached picture

Hope it will help you...

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6 0

3 years ago

Can someone SMART redo these questions I mean I made a seven and I did all I could I need to know what went wrong

adoni [48]

2. 8x -28 = -140
8x -28 + 28 = -140 + 28
8x = -112
8x/8 = -112/8
x = -14

3. -9 + x/3 = -23
-9 + 9 + x/3 = -23 + 9
x/3 = -14
x/3/3 = -14/3
x = -14/3

4. x/-1.5 - 3.5 = -13.5
x/-1.5 - 3.5 + 3.5 = -13.5 + 3.5
x/1.5 = -10
x/-1.5/-1.5= -10/-1.5
x = 20/3

5.-6(x + 3) = -36
-6x - 18 = -36
-6x - 18 + 18 = -36 + 18
-6x = -18
-6x/-6 = -18/-6
x = 3

6. k + 3.7/9.8 = -0.22
k + 3.7/9.8/9.8 = -0.22/9.8
k + 3.7 = -2.156
k + 3.7 - 3.7 = -2.156 - 3.7
k = -5.856

7. 12(x - 6) = -108
12x - 72 = -108
12x - 72 + 72 = -108 + 72
12x = -36
12x/12 = -36/12
x = -3

8. -21.83x - -19.9 = -23.83
-21.83x + 19.9 = -23.83
-21.83x + 19.9 - 19.9 = -23.83 - 19.9
-21.83x = -43.73
-21.83x/-21.83 = -43.73/-21.83
x = 2

9. -10x - 68 + x = 40
-9x - 68 = 40
-9x -68 + 68 = 40 + 68
-9x = 108
-9x/-9 = 108/-9
x = -12

10. -34 - 3x - 2x = 71
-34 - 5x = 71
-34 + 34 - 5x = 71 + 34
-5x = 105
-5x/-5 = 105/-5
x = -21

11. 3x - 77 - 8x = 23
-5x - 77 = 23
-5x - 77 + 77 = 23 + 77
-5x = 100
-5x/-5 = 100/-5
x = -20

12. 3x - 5(2x - 12) = 123
3x - 10x + 60 = 123
-7x + 60 = 123
-7x + 60 - 60 = 123 - 60
-7x = 63
-7x/-7 = 63/-7
x = -9

13. -3x + 6(x + 6) = 15
-3x + 6x + 36 = 15
3x + 36 = 15
3x + 36 - 36 = 15 - 36
3x = -21
3x /3 = -21/3
x = -7

14. 5x + 2(4x - 9) = -174
5x + 8x - 18 = -174
13x - 18 = -174
13x - 18 + 18 = -174 + 18
13x = -156
13x/13 = -156/13
x = -12

15. -3x + 6(5x + 3) = -171
-3x + 30x + 18 = -171
27x + 18 = -171
27x + 18 - 18 = -171 - 18
27x = -189
27x/27 = -189/27
x = -7

5 0

3 years ago

Find the slope (or grade) of the treadmill shown. The grade of the treadmill is___%

prisoha [69]

Answer:

grade=15%

Step-by-step explanation:

For 2 ft on x-axis it has elevated 0.3 ft on y-axis

m=0.3/2=0.15 ft

grade=m x 100

grade=15%

6 0

3 years ago

**please give me the steps to solve this, will mark brainlyest if leads to correct answer**

please give me the steps to solve this, will mark brainlyest if leads to correct answer