The second one because it has a proportional relationship
16.25 penalties.
35% of 25 is 8.75.
25-8.75=16.25
Ok so if you notice every choice is solved for a, all you have to do is isolate "a" in 7a-8b=10x. Start by moving 8b to the other side and to change the sign. Now it is 7a = 10x + 8b. Then divide everything by 7 and you get a = (10x + 8b)/7
A-b = 43----(1)
a+b = 13----(2)
(1)+(2) 2a=56
then a=56/2= 28
so b=13-28= -15
so that the numbers are -15 and 28
