Question

assume f is a one to one function. f(x) = -5-10x, find f^-1 (-15).

f^-1(-15) =_____

Answer 1

set
\[-15=-5-10x\] solve for x

Answer 2

\[-10=-10x\]\[x=1\]

Answer 3

so since
\[f(1)=-15\] that means
\[f^{-1}(-15)=1\]