40% of Peter’s salary is equal to 25% of Jason’s salary. If Jason’s salary is $684 more than Peter’s salary, how much money do they have altogether?

Answer 1

j = p+684
0.4p = 0.25j
0.4p = 0.25(p+684)
0.15p = 171
p = 1140
j+p = 1140 + 1140+684 = 2964

Answer 2

Peter's salary --- x
Jason's salary --- y

Let's just translate the English into Math.

"40% of Peter’s salary is equal to 25% of Jason’s salary"
----> (40/100)x = (25/100)y
40x = 25y
8x = 5y
y = (8/5)x

"Jason’s salary is $684 more than Peter’s salary"
tells me that if I subtract Peter's salary from Jason's, I will get 684
y - x = 684
substitute ....
(8/5) x - x = 684
(3/5)x = 684
x = 684(5/3) = 1140
since y = (8/5)x
y = (8/5)(1140) = 1824

the mystery is solved! Just state your conclusions.