Question

If x varies directly as y, find x when y=8. x=11 when y=-3

Answer 1

`x=-(88)/(3)`

Explanation:

When a quantity "A" varies DIRECTLY with another quantity "B", we can write the proportionality equation as:

A = kB

Where k is the proportionality constant (to be found)

In this problem, it is given x varies DIRECTLY with y, so we can write:

x = ky

Also, given, x = 11, y = -3, so we plug these into the equation and first find k:

x = ky

11 = k(-3)

k = -11/3

Now, we need to find x when y = 8, so we substitute and find x:

`x=ky\\x=(-(11)/(3))(8)\\x=-(88)/(3)`