to solve
f(x)=15000+1.5x
replace f(x) with y
switch x and y
solve for y
replace y with f⁻¹(x)
f(x)=15000+1.5x
replce f(x) with y
y=15000+1.5x
switch x and y
x=15000+1.5y
solve for y
y=(x-15000)/1.5
f-1(x) = (x-15000)/1.5
The variable x
represents the spending limit on johns credit card In the inverse
function.
If johns
spending limit is $60000, his monthly income is (60000-15000)/1.5=$30000
If johns
spending limit is $60,00, his monthly income is (60-15000)/1.5= -$9960------
>the johns spending limit must be >$15000
