Find the solution set for the system of equations.
9x + 5y = 28
5x + 9y = 56

9x + 5y = 28 . . . . . (1)
5x + 9y = 56 . . . . . (2)

(1) x 5 => 45x + 25y = 140 . . . . . (3)
(2) x 9 => 45x + 81y = 504 . . . . . (4)

(3) - (4) => --56y = -364 => y = 6.5

From (1), 9x + 5(6.5) = 28 => 9x = 28 - 32.5 = -4.5 => x = -4.5/9 = -0.5

If jon had $4.00 then takes away $2.25, then he should have $1.75 left. $4.00 - $2.25 = $1.75 hope this ; )