Question

Suppose that y varies directly with x and y=-21 when x=7. find the value of x when y=18

Answer 1

x=6

Explanation:

First, we have to find how the x value equals the y value. What do we have to do to x to get y? We have to multiply 7 by -3 to get -21. This means that y=-3x.

We know that x=18, so all we need to do is substitute it in.

18=-3x

`(18)/(-3) =(-3x)/(-3)`

-6=x

Answer 2

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