42=x+3(2x+1)

Solution for 42=x+3(2x+1) equation:

Simplifying
42 = x + 3(2x + 1)

Reorder the terms:
42 = x + 3(1 + 2x)
42 = x + (1 * 3 + 2x * 3)
42 = x + (3 + 6x)

Reorder the terms:
42 = 3 + x + 6x

Combine like terms: x + 6x = 7x
42 = 3 + 7x

Solving
42 = 3 + 7x

Solving for variable 'x'.

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

Add '-7x' to each side of the equation.
42 + -7x = 3 + 7x + -7x

Combine like terms: 7x + -7x = 0
42 + -7x = 3 + 0
42 + -7x = 3

Add '-42' to each side of the equation.
42 + -42 + -7x = 3 + -42

Combine like terms: 42 + -42 = 0
0 + -7x = 3 + -42
-7x = 3 + -42

Combine like terms: 3 + -42 = -39
-7x = -39

Divide each side by '-7'.
x = 5.571428571

Simplifying
x = 5.571428571