F-1(3)=3-4(3)

Solution for F-1(3)=3-4(3) equation:

Simplifying
F + -1(3) = 3 + -4(3)

Multiply -1 * 3
F + -3 = 3 + -4(3)

Reorder the terms:
-3 + F = 3 + -4(3)

Multiply -4 * 3
-3 + F = 3 + -12

Combine like terms: 3 + -12 = -9
-3 + F = -9

Solving
-3 + F = -9

Solving for variable 'F'.

Move all terms containing F to the left, all other terms to the right.

Add '3' to each side of the equation.
-3 + 3 + F = -9 + 3

Combine like terms: -3 + 3 = 0
0 + F = -9 + 3
F = -9 + 3

Combine like terms: -9 + 3 = -6
F = -6

Simplifying
F = -6