5(3+f+6)=20

Solution for 5(3+f+6)=20 equation:

Simplifying
5(3 + f + 6) = 20

Reorder the terms:
5(3 + 6 + f) = 20

Combine like terms: 3 + 6 = 9
5(9 + f) = 20
(9 * 5 + f * 5) = 20
(45 + 5f) = 20

Solving
45 + 5f = 20

Solving for variable 'f'.

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

Add '-45' to each side of the equation.
45 + -45 + 5f = 20 + -45

Combine like terms: 45 + -45 = 0
0 + 5f = 20 + -45
5f = 20 + -45

Combine like terms: 20 + -45 = -25
5f = -25

Divide each side by '5'.
f = -5

Simplifying
f = -5