Question

How to solve 3n+9=7n-15

Answer 1

Simplifying 3n + 9 = 7n + -15
9 + 3n = 7n + -15
9 + 3n = -15 + 7n
9 + 3n = -15 + 7n

9 + 3n + -7n = -15 + 7n + -7n
3n + -7n = -4n 9 + -4n = -15 + 7n + -7n
7n + -7n = 0 9 + -4n = -15 + 0 9 + -4n = -15
9 + -9 + -4n = -15 + -9
9 + -9 = 0 0 + -4n = -15 + -9 -4n = -15 + -9
-15 + -9 = -24 -4n = -24
Divide each side by -4
n = 6 

Answer 2

The answer to this problem is 6