Answer:
u = 7
Explanation:
First do distributive property to 2(u+3) this makes it -15=-5u+2u+6.
Then combine like terms: -15= -3u +6 (the positive u's cancel out the negative u's)
get U by itself by subtracting 6 from both sides: -21= -3u
Divide both side by -3: -21/-3 = -3u/-3
Answer is 7= u
Check your answer: Plug in 7
-15 = -5(7)+ 2(7+3)
-15= -35 + 14+6
-15= -35+20
-15=-15