-123=3(1-7x)

Solution for -123=3(1-7x) equation:

Simplifying
-123 = 3(1 + -7x)
-123 = (1 * 3 + -7x * 3)
-123 = (3 + -21x)

Solving
-123 = 3 + -21x

Solving for variable 'x'.

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

Add '21x' to each side of the equation.
-123 + 21x = 3 + -21x + 21x

Combine like terms: -21x + 21x = 0
-123 + 21x = 3 + 0
-123 + 21x = 3

Add '123' to each side of the equation.
-123 + 123 + 21x = 3 + 123

Combine like terms: -123 + 123 = 0
0 + 21x = 3 + 123
21x = 3 + 123

Combine like terms: 3 + 123 = 126
21x = 126

Divide each side by '21'.
x = 6

Simplifying
x = 6