I will show you how to do #5:
a). -20 + 2(n-1) Original Expression
-20 +2n - 2 Distributive Property
-22 + n Combine Like Terms
Final Expression: -22 + n
b). 1.5 + (-2.5)(n -1) Original Expression
1.5 + -2.5n + 2.5 Distributive Property
4 - 2.5n Combine Like Terms
Final Expression: 4 - 2.5n
