Answer: (x,y) = (5,4)
Step-by-step explanation: 3x+4y=31 & 2x-4y=-6 goes to 5x=25, then divide both by 5 to get x=5. Next, you substitute x substitute; 2 x 5 -4y=-6 goes into y=4. Then do 3 x 5 + 4 x 4 = 31 & 2 x 5 - 4 x 4 =-6, which will equal 31 = 31 & -6 = -6. So, (x,y) = (5,4).