We have to solve the equation: 5(u-5)+10=12u+3(u+5)

First open the brackets

5(u-5)+10=12u+3(u+5)

=> 5u - 25 + 10 = 12u + 3u + 15

bring the terms with u to one side and the numeric terms to the other.

=> 5u - 12u - 3u = 15 + 25 - 10

=> -10u = 30

=> u = -30/10

=> u = -3

**Therefore u = -3**