it gives you x, so simply SUBSTITUTE it in for x
2(7-2y) + 9y = 44 multiply out the 2 or Distribute it
14 - 4y + 9y =44 now put the y's together
14 + 5y = 44 subtract 14 to both sides
5y = 30 finally divide each side by 5
y = 6 (use this value to find x by plugging it in for y)
2x + 9(6) = 44
2x + 54 =44 subtract 54 from both sides
2x = -10 divide 2 on both sides
x = -5, y= 6
check: 2(-5) + 9(6) = ?
-10 + 54 = 44
44=44 so it checks out ^^