The answer is u = 2.
Here are the steps.
1. expand ( -2u + 10 = -9u + 24)
2. subtract 10 from both sides ( -2u = -9u + 24 - 10
3. Simplify -9u + 24 - 10 to 9u + 14 ( -2u = -9u + 14)
4. add 9u to both sides ( -2u + 9u = 14)
5. simplify -2u + 9u to 7u ( 7u = 14)
6. divide both sides by 7 ( u = 14/7)
7 simplify 14/7 to 2 ( u = 2)