Question

Ming is given the following function and asked to find b. f(x)=15(b)x If f(4) = 1215, what is one possible value of b?

Answer 1

Explanation:

f(x) = 15(b)x

f(4) = 1215

15(b)4 = 1215

(15)(4)b = 1215

60b = 1215

60b / 60 = 1215 / 60

b = 20.25

Check the answer

15 * 20.25 * 4 = 1215

Answer 2

3

Explanation:

if you did this on prepworks its 3.

1215=15(b)4

121515=(b)4

81=b4

92=b4

(32)2=b4

34=b4

b = ±3