-n(3n+4n)=-28

Solution for -n(3n+4n)=-28 equation:

Simplifying
-1n(3n + 4n) = -28

Combine like terms: 3n + 4n = 7n
-1n(7n) = -28

Remove parenthesis around (7n)
-1n * 7n = -28

Reorder the terms for easier multiplication:
-1 * 7n * n = -28

Multiply -1 * 7
-7n * n = -28

Multiply n * n
-7n2 = -28

Solving
-7n2 = -28

Solving for variable 'n'.

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

Divide each side by '-7'.
n2 = 4

Simplifying
n2 = 4

Take the square root of each side:
n = {-2, 2}