= , (1) 3(m-n) = m-10. (2) Multiply equation (1) by 60 (both sides). You will get an equivalent equation 30m + 30n = 78. (1') Simplify equation (2) step by step. You will get equivalent equations 3m - 3n = m - 10, 2m - 3n = -10, 20m - 30n = -100. (2') Now add equations (1') and (2') (both sides). You will get 50 m = 78 - 100 = -22. Hence, m = = . Now from equation (1) = = = = = . Hence, n = = . Answer. n = , m = .