2(1[2u+7]1)=42

Solution for 2(1[2u+7]1)=42 equation:

Simplifying
2(1[2u + 7] * 1) = 42

Reorder the terms:
2(1[7 + 2u] * 1) = 42

Reorder the terms for easier multiplication:
2(1 * 1[7 + 2u]) = 42

Multiply 1 * 1
2(1[7 + 2u]) = 42
2([7 * 1 + 2u * 1]) = 42
2([7 + 2u]) = 42
(7 * 2 + 2u * 2) = 42
(14 + 4u) = 42

Solving
14 + 4u = 42

Solving for variable 'u'.

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

Add '-14' to each side of the equation.
14 + -14 + 4u = 42 + -14

Combine like terms: 14 + -14 = 0
0 + 4u = 42 + -14
4u = 42 + -14

Combine like terms: 42 + -14 = 28
4u = 28

Divide each side by '4'.
u = 7

Simplifying
u = 7