3(7x-21)-42=63

Solution for 3(7x-21)-42=63 equation:

Simplifying
3(7x + -21) + -42 = 63

Reorder the terms:
3(-21 + 7x) + -42 = 63
(-21 * 3 + 7x * 3) + -42 = 63
(-63 + 21x) + -42 = 63

Reorder the terms:
-63 + -42 + 21x = 63

Combine like terms: -63 + -42 = -105
-105 + 21x = 63

Solving
-105 + 21x = 63

Solving for variable 'x'.

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

Add '105' to each side of the equation.
-105 + 105 + 21x = 63 + 105

Combine like terms: -105 + 105 = 0
0 + 21x = 63 + 105
21x = 63 + 105

Combine like terms: 63 + 105 = 168
21x = 168

Divide each side by '21'.
x = 8

Simplifying
x = 8