Answer:
u = 1
Step-by-step explanation:
Move the variable to the left-hand side and change the sign. 8u + 4u - 7 = 5. Move the constant to the right-hand side and change it's sign. 8u + 4u = 5+7. Now add the like terms. 8u + 4u = 12u. 5 + 7 = 12. Lastly, divide both sides by 12. 12u/12 cancels each other out. 12/12 = 1. u=1
