Question

Determine the value of x in each of the expressions which leads to an input of 12 to the function f(x):
(a) f( 4 x ) = f( 12 ) when
x =

(b) f \left( \frac{1}{4} x \right) = f( 12 ) when
x =

(c) f( x - 3 ) = f( 12 ) when
x =

(d) f( -x ) = f( 12 ) when
x =

do i just plug in 12 to x?