Philip P. answered 04/16/19
Effective and Patient Math Tutor
You actually need two (x,y) points to figure out the equation. Suppose you are given the points (1,6) and (3,54). Here are the steps.
1) Plug in both points:
y = abx
6 = ab1
54 = ab3
2) To find the value of b, take the ratio of the two:
54/6 = ab3/ab1
9 = b2
3 = b
So your equation so far is y = a·3x
3) To find the value of a, plug in one of the two points and solve for a:
y = a·3x
Plug in (1,6)
6 = a·31
2 = a
The final equation is y = 2·3x
Ellie V.
Thank you so much.04/16/19