Question

I don't want the answer, but I want to know how you got that answer.

Answer 1

Answer:

n = 5

Step-by-step explanation:

$4n+5n+15=5n+7n\\\\9n+15=12n\\\\9n+15-15=12n-15\\\\-3n=-15\\\\\frac{-3n=-15}{-3}\\\\ \boxed{n=5}$

Hope this helps.