Answer:
u=5
Step-by-step explanation:
1. Distribute 8 through the parentheses
-1=8u-56+3u
2. Collect like terms.
-1=11u-56
3. Move the variable to the left-hand side and change its sign.
1-11u=-56
4. Calculate the sum
-11=-55
5. Divide both sides by -11
u=5