3(1[3u-5]1)=12

Solution for 3(1[3u-5]1)=12 equation:

Simplifying
3(1[3u + -5] * 1) = 12

Reorder the terms:
3(1[-5 + 3u] * 1) = 12

Reorder the terms for easier multiplication:
3(1 * 1[-5 + 3u]) = 12

Multiply 1 * 1
3(1[-5 + 3u]) = 12
3([-5 * 1 + 3u * 1]) = 12
3([-5 + 3u]) = 12
(-5 * 3 + 3u * 3) = 12
(-15 + 9u) = 12

Solving
-15 + 9u = 12

Solving for variable 'u'.

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

Add '15' to each side of the equation.
-15 + 15 + 9u = 12 + 15

Combine like terms: -15 + 15 = 0
0 + 9u = 12 + 15
9u = 12 + 15

Combine like terms: 12 + 15 = 27
9u = 27

Divide each side by '9'.
u = 3

Simplifying
u = 3