Answer:
1. n = 2
2. -4 = r
Step-by-step explanation:
-n - 7n = -16
subtract the like terms, like terms are terms that have the same variable or power. Ex: n and 7n are like terms as they both have n, however 7n and 16 are not. x^2 and x are not like terms as they do not have the same power so:
-8n = -16
divide both sides by -8
n = 2
-20 = 3r + 2r
add like terms
-20 = 5r
divide 5 from both sides
-4 = r
