Twice a first number decreased by a second number is 11. The first number increased by twice the second number is 18. Find the numbers. The numbers are (Use a comma to separate answers as needed.) Solution Let x be the first number and y be the second number 2x-y=11 x+2y=18 4x-2y=22 x+2y=18 Adding abive equations 5x=40 x=8 8+2y=18 y=5.