Answer:
[tex]7 {u}^2 - 14u + 14[/tex]
Step-by-step explanation:
We want to simplify
[tex](8 {u}^{2} - 9u + 5) - (9 {u}^{2} + 2u - 2) + (8{u}^{2} + 7u + 7)[/tex]
We expand the parenthesis to get:
[tex]8 {u}^{2} - 9u + 5 - 9 {u}^{2} - 2u + 2 + 8{u}^{2} + 7u + 7[/tex]
We combine similar terms to obtain:
[tex]8 {u}^{2} + 8{u}^{2} - 9 {u}^{2} - 9u - 2u + 7u + 7 + 5 + 2[/tex]
We finally simplify to obtain:
[tex]7 {u}^2 - 14u + 14[/tex]
