If y=-12 when x=6, then what is x when y=26

Question

Y varying directly as X. In a direct variation equation.

Answer 1

Hi! I agree with an answer already submitted; however, I used a different formula to calculate it.

Direct Variation

“Y varying directly as x” means that y and x always have the same ratio.

k is known as the constant of variation

k = y / x

k = -12 / 6

k = -2

When k<0 (k is negative),

If x increases then the value of y decreases, or if x decreases then the value of y increases.

-2 = y / x

-2 = 26 / x

x = -2 / 26

x = -13

Answer 2

This is an important concept particularly when trying to scale up ingredients on a cook book. I am going to use the equation x₁ / y₁ = x₂ / y₂ So x₂= 6 y₁ = -12 y₂ = 26

Plug in values into the equation

6 / -12 = (x₂) / 26

-12(x₂) = 156

x₂ = -13

Answer 3

Let me guess that "direct variation" means that y is directly proportional to x---meaning that y increases in proportion to an increase in x. In other words, a straight line relationship with a positive slope..

The only way to solve it is to assume the slope is 1.

So, if y increases by 38 units, then x must have the same increase. 6 + 38 = 44