Write the equation of the exponential function that passes through the points (-1,10) and (-3,40)

Question

Write the equation of the exponential function that passes through the points (-1,10) and (-3,40)

Answer 1

f(x) = ab^x

10 = ab^-1

40 = ab^-3

1/4 = b² First equation divided by second

10 = a(1/2)^-1

10 = 2a

5 = a

f(x) = 5(0.25)^x