The answer is 100N all you have to do is multiply 5 by 20.
First you can solve for b: Subtract a on both sides and get 2b=-a+10, then divide by 2 to get b by itself and get: b=-1/2a+5
Then you can plug in this equation for b in the other: This would give you: 2a+-1/2a+5=6. Then you can use that equation to solve for a and get: 1.5a+5=6, subtract 5, 1.5a=1, divide by 1.5, a=1/1.5
Then you can plug in the value of a to solve for b.
Answer:
|-13| = 13, so the opposite is -13
|14| = 14, the opposite is -14
-|42| = -42, the opposite is 42
