21x - 21y = 48 + 20x x - 21y = 48 x = 48 + 21y
19y + 19x = 100 + 12x 19y + 7x = 100 19x + 7(48 + 21y) = 100
x = 48 + 21y x = 48 + 21y x = 48 + 21y
19y + 336 + 147y = 100 336 + 166y = 100 166y = -236
x = 48 + 21y x = 48 + 21y x = 48 + 21*(-1 35/83) x = 48 - 29 71/83
y = -236 : 166 y = -1 35/83 y = -1 35/83 y = -1 35/83
x = 18 12/83
y = -1 35/83