From the second equation: y=48-x. Substitute for y in the first equation: 2(48-x)+3x=112; 96-2x+3x=112; 96+x=112; x=112-96=16 (subtracting 96 from each side). So y=48-16=32 from 1st eqn.
Check out the result by substituting values for x and y in each equation: 64+48=112; 32+16=48. Correct!