Question

If (-3, y) lies on the graph of y = 3^-x, then y =

Answer 1

Because (-3, y) is a solution of y = 3^-x, substitute -3 into the equation for x. So y = 3^-(-3) = 3^3 = 3 x 3 x 3  = 27. Answer y = 27, the point is (-3, 27)

Answer 2

Simply plug in x= -3 in to y = 3^-x, and solve for y.


`y=3^(-(-3))\\\\y = 3^3\\\\\boxed{\bf{y=27}}`

So, the point (-3, 27) lies on the graph of y = 3^-x.

Your final answer is y = 27.