Solve. −9.8+(−5.9)+u=−12.4
u=?
a: 3.3
b: -8.5
c: -28.1
d: 15.7

The best way to solve this is to simply substitute all given answers for u.

The answer is A) 3.3

The answer is A, 3.3. You first want to distribute the + symbol to the 5.9, which will make it still a negative. From then you want to combine like terms so you can add -9.8+-5.9. That should be equal to -15.7. Your equation now is looking like -15.7+u=-12.4. You want to leave the u alone so now you have to do the opposite of -15.7 which is add 15.7. What you do to one side, you do to the other. Now add 15.7 to -12.4. That should be 3.3. Now it looks like u=3.3 which is your answer.