Answer:
The correct answer to this problem is u = -8.
Explanation:
To solve this problem, we first must combine like terms on the left side of the equation. This means adding together the two terms that have a "u" multiplied by a number. To combine them, we simply add the coefficients together, as we would with constant values. This is modeled below:
-18u+16u-7=9
-2u - 7 = 9
Next, we want to add 7 to both sides of the equation. This will cancel out the -7 on the left side of the equation, isolating the term with the variable u (what we are trying to solve for).
-2u - 7 + 7 = 9 + 7
-2u = 16
Finally, we want to divide both sides by -2 in order to isolate the variable u. This will get rid of the coefficient of negative 2 and give us our answer.
u = 16/-2 = -8
Therefore, the answer to this question is u = -8.
Hope this helps!