2n+3(n+2)=21

Solution for 2n+3(n+2)=21 equation:

Simplifying
2n + 3(n + 2) = 21

Reorder the terms:
2n + 3(2 + n) = 21
2n + (2 * 3 + n * 3) = 21
2n + (6 + 3n) = 21

Reorder the terms:
6 + 2n + 3n = 21

Combine like terms: 2n + 3n = 5n
6 + 5n = 21

Solving
6 + 5n = 21

Solving for variable 'n'.

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

Add '-6' to each side of the equation.
6 + -6 + 5n = 21 + -6

Combine like terms: 6 + -6 = 0
0 + 5n = 21 + -6
5n = 21 + -6

Combine like terms: 21 + -6 = 15
5n = 15

Divide each side by '5'.
n = 3

Simplifying
n = 3