⑦
8x3-11y12=1 5x12-13y16=176
8x3-11y12=1…(1) 5x12-13y16=176…(2)
(1)×12
32x-11y=12…(1)'
(2)×48
20x-39y=136…(2)'
(1)'×5-(2)'×8
160x-55y=60-)160x-312y=1088 257y=-1028 y=-4…(3)
(3)を(1)'に代入
32x-11×(-4) = 12
32x +44=12
32x = 12-44
32x =-32
x = -1
