2x + 5y = 85 (1) ("The sum of twice a first number and five times a second number is 85.") 5x - y = 37 (2) ("If the second number is subtracted from five times the first number the result is 37.") Multiply the second equation by 5. Keep equation (1) as is. You will get 2x + 5y = 85 (1') 25x - 5y = 185 (2') Add equations (1' and (2'). 27x = 85 + 185 = 270 ====> x = 270/27 = 10. Then from eq(2) y = 5x - 37 = 5*10 - 37 = 50 - 37 = 13. Answer. x= 10, y= 13.