x+x+1+x+2+x+3=7(x+3)

Solution for x+x+1+x+2+x+3=7(x+3) equation:

Simplifying
x + x + 1 + x + 2 + x + 3 = 7(x + 3)

Reorder the terms:
1 + 2 + 3 + x + x + x + x = 7(x + 3)

Combine like terms: 1 + 2 = 3
3 + 3 + x + x + x + x = 7(x + 3)

Combine like terms: 3 + 3 = 6
6 + x + x + x + x = 7(x + 3)

Combine like terms: x + x = 2x
6 + 2x + x + x = 7(x + 3)

Combine like terms: 2x + x = 3x
6 + 3x + x = 7(x + 3)

Combine like terms: 3x + x = 4x
6 + 4x = 7(x + 3)

Reorder the terms:
6 + 4x = 7(3 + x)
6 + 4x = (3 * 7 + x * 7)
6 + 4x = (21 + 7x)

Solving
6 + 4x = 21 + 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.
6 + 4x + -7x = 21 + 7x + -7x

Combine like terms: 4x + -7x = -3x
6 + -3x = 21 + 7x + -7x

Combine like terms: 7x + -7x = 0
6 + -3x = 21 + 0
6 + -3x = 21

Add '-6' to each side of the equation.
6 + -6 + -3x = 21 + -6

Combine like terms: 6 + -6 = 0
0 + -3x = 21 + -6
-3x = 21 + -6

Combine like terms: 21 + -6 = 15
-3x = 15

Divide each side by '-3'.
x = -5

Simplifying
x = -5