Question

Given the function ƒ(x ) = 9 - 2x, find x when ƒ(x ) = 25.

-41

17

-8

Answer 1

f(x)=9-2x
--------------------
f(x)=25
9-2x=25
-9     -9

-2x=16
/-2   /-2

x = -8
---------------------
f(x)=-41
9-2x=-41
-9      -9

-2x=-50
/-2   /-2

x = 25
----------------------
f(x)=17
9-2x=17
-9     -9

-2x=8
/-2  /-2

x = -4
-----------------------
f(x)=-8
9-2x=-8
-9     -9

-2x=-17
/-2   /-2

x = -17/2