Question

Given f(x) = 3/4x + 12, find the value of x when f(x) = x.

Answer 1

x=48

Explanation:

f(x) is basically just another way to write y.

If f(x)=x, then y=x.

x=3/4x+12 (Original Equation Substituting x for f(x), equal to y)

1/4x=12 (Subtract 3/4 from both sides of the linear equation)

x=48 (Multiply both sides by 4)

Answer 2

48 =x

Explanation:

3/4x + 12 = x

Subtract 3/4 x from each side

3/4x + 12-3/4x = x-3/4x

12 = 1/4x

Multiply each side by 4

12*4 =1/4x *4

48 =x