15 and 4 are the factors of 120 that add up to 19.
146
-10 and 2 -12 and 4 -20 and 12
None of the factor pairs of 120 add up to -14. If that was -120, you could use -20 and 6.
-1, 6 and -12.
31
If something costs $120 plus 20%, you would add 20% of $120 to $120. To find out the cost, you would calculate 20% of $120, which is $24, and add it to $120 to get a total of $144.
To find factors that add up to 240 and also add up to 140, we need to solve a system of equations. Let's represent the two factors as x and y. We have the equations x + y = 140 and x + y = 240. By solving this system, we find that the factors are 100 and 140.
26
34
79
-13