I have a function:

f(x) = 10.767(1.346)^x

I have found the area below the graph between x = -8, and x= 0, below y = 8. This comes out to 31.557.

I need to change my function f(x) so that the area between x -8, x = 0, below y = 8 is equal to different areas.

The areas I am testing are:

1.25 (31.557)

1.5(31.557)

2(31.557)

How would I go about doing this?, It's been bugging me.