Hi, I just started learning about direct, joint, and inverse variation. I was doing a practice question and got -18 when the answer is -8. I'm having trouble solving the problem because my book only shows me how to find y not x. Please help me.
If y varies inversely as x and y=-14 when x=12, find x when y=21.
2 answers
Nvm I figured it out.
we know that xy = k, a constant
So, we need x such that
21x = -14*12
x = -8
You can see how to solve it without knowing what k is. The more usual method is to do
xy = k
-14*12 = k
k = -168
So, when y=21,
21x = -168
x = -8
Too bad you didn't show your work ...
So, we need x such that
21x = -14*12
x = -8
You can see how to solve it without knowing what k is. The more usual method is to do
xy = k
-14*12 = k
k = -168
So, when y=21,
21x = -168
x = -8
Too bad you didn't show your work ...
6 answers