All categories

3 years ago

If y varies inversely with x and y =5 when x=20 find x when y = -4

Mathematics

1 answer:

sweet-ann [11.9K]3 years ago

7 0

Answer:

x=-25

Step-by-step explanation:

Inverse variation

xy =k

We know x and y

20*5 =k

100 =k

So the formula is

x y = 100

We know y = -4

x (-4) = 100

Divide each side by -4

-4x/-4 = 100/-4

x = -25

You might be interested in

Suppose that 15 years ago, a benefactor set up an account for your education. This benefactor made a single deposit of $20,000 t

drek231 [11]

Answer:

No it wont

Step-by-step explanation:

7 0

3 years ago

Write the equation of a line that is perpendicular to x = -1 and that passes through the Point (8, -4).

pychu [463]

Answer:

y = - 4

Step-by-step explanation:

x = - 1 is the equation of a vertical line parallel to the y- axis

The equation of a line perpendicular to it will therefore be a horizontal line parallel to the x- axis with equation

y = c

where c is the value of the y- coordinates the line passes through.

The line passes through (8, - 4 ) with y- coordinate - 4 , then

y = - 4 ← equation of perpendicular line

7 0

3 years ago

HELPPPPPP PLEASE ...

horsena [70]

Answer:72828

Step-by-step explanation:

5 0

3 years ago

Read 2 more answers

What is the formula of a²-b²?

Thepotemich [5.8K]

Answer:

The formula of a²-b² are as follows:

Step-by-step explanation:

(a-b)(a+b)

5 0

3 years ago

Read 2 more answers

Please help me with #'s 5&6

Fynjy0 [20]

$5.\\(x+3)^2+7=-2\qquad|-7\\\\(x+3)^2=-9 < 0\\\\\text{NO REAL SOLUTION}\\\\(x+3)^2=-9\to x+3=\pm\sqrt{-9}\\\\x+3=-3i\ \vee\ x+3=3i\qquad|-3\\\\\boxed{x=-3-3i\ \vee\ x=-3+3i}$

$6.\\4(x-10)^2=25\qquad|:4\\\\(x-10)^2=\dfrac{25}{4}\to x-10=\pm\sqrt{\dfrac{25}{4}}\\\\x-10=-\dfrac{\sqrt{25}}{\sqrt4}\ \vee\ x-10=\dfrac{\sqrt{25}}{\sqrt4}\\\\x-10=-\dfrac{5}{2}\ \vee\ x-10=\dfrac{5}{2}\\\\x-10=-2.5\ \vee\ x-10=2.5\qquad|+10\\\\\boxed{x=7.5\ \vee\ x=12.5}$

7 0

4 years ago

If y varies inversely with x and y =5 when x=20 find x when y = -4​

If y varies inversely with x and y =5 when x=20 find x when y = -4