(X+3)+3(X+1)=20

Solution for (X+3)+3(X+1)=20 equation:

Simplifying
(X + 3) + 3(X + 1) = 20

Reorder the terms:
(3 + X) + 3(X + 1) = 20

Remove parenthesis around (3 + X)
3 + X + 3(X + 1) = 20

Reorder the terms:
3 + X + 3(1 + X) = 20
3 + X + (1 * 3 + X * 3) = 20
3 + X + (3 + 3X) = 20

Reorder the terms:
3 + 3 + X + 3X = 20

Combine like terms: 3 + 3 = 6
6 + X + 3X = 20

Combine like terms: X + 3X = 4X
6 + 4X = 20

Solving
6 + 4X = 20

Solving for variable 'X'.

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

Add '-6' to each side of the equation.
6 + -6 + 4X = 20 + -6

Combine like terms: 6 + -6 = 0
0 + 4X = 20 + -6
4X = 20 + -6

Combine like terms: 20 + -6 = 14
4X = 14

Divide each side by '4'.
X = 3.5

Simplifying
X = 3.5