20=3(x-1)-(x-9)

Solution for 20=3(x-1)-(x-9) equation:

Simplifying
20 = 3(x + -1) + -1(x + -9)

Reorder the terms:
20 = 3(-1 + x) + -1(x + -9)
20 = (-1 * 3 + x * 3) + -1(x + -9)
20 = (-3 + 3x) + -1(x + -9)

Reorder the terms:
20 = -3 + 3x + -1(-9 + x)
20 = -3 + 3x + (-9 * -1 + x * -1)
20 = -3 + 3x + (9 + -1x)

Reorder the terms:
20 = -3 + 9 + 3x + -1x

Combine like terms: -3 + 9 = 6
20 = 6 + 3x + -1x

Combine like terms: 3x + -1x = 2x
20 = 6 + 2x

Solving
20 = 6 + 2x

Solving for variable 'x'.

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

Add '-2x' to each side of the equation.
20 + -2x = 6 + 2x + -2x

Combine like terms: 2x + -2x = 0
20 + -2x = 6 + 0
20 + -2x = 6

Add '-20' to each side of the equation.
20 + -20 + -2x = 6 + -20

Combine like terms: 20 + -20 = 0
0 + -2x = 6 + -20
-2x = 6 + -20

Combine like terms: 6 + -20 = -14
-2x = -14

Divide each side by '-2'.
x = 7

Simplifying
x = 7