First step find a common multiple, e.g. 45 and subtract
9x + 5y = 28 * 5
5x + 9y = 56 * 9
45x + 25y = 140
-(45x + 81y = 504)
-56y = -364
56y = 364
y = 6.5
Substitute into any equation
9x + 5(6.5) = 28
9x + 32.5 = 28
9x = -4.5
x = -0.5
x = -0.5 , y = 6.5