Given that f(x) = 2x − 5, find the value of x that makes f(x) = 15

Question

A.5
B.10
C.20
D.25

Answer 1

2 x - 5 = 15

add 5 to both sides

2 x = 20

multiply both sides by 1/2

x = 10

==============
check
2 (10) - 5
20 - 5
15 sure enough