u=3(7n+30)+6(n-1)

Solution for u=3(7n+30)+6(n-1) equation:

Simplifying
u = 3(7n + 30) + 6(n + -1)

Reorder the terms:
u = 3(30 + 7n) + 6(n + -1)
u = (30 * 3 + 7n * 3) + 6(n + -1)
u = (90 + 21n) + 6(n + -1)

Reorder the terms:
u = 90 + 21n + 6(-1 + n)
u = 90 + 21n + (-1 * 6 + n * 6)
u = 90 + 21n + (-6 + 6n)

Reorder the terms:
u = 90 + -6 + 21n + 6n

Combine like terms: 90 + -6 = 84
u = 84 + 21n + 6n

Combine like terms: 21n + 6n = 27n
u = 84 + 27n

Solving
u = 84 + 27n

Solving for variable 'u'.

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

Simplifying
u = 84 + 27n