(1)*10,
8x-9y=20,
(2)*3,
18x-9y=7.5,
相减,
10x=12.5,
x=5/4,
y=10/9 (1)*10,
8x-9y=20,
(2)*3,
18x-9y=7.5,
相减,
10x=12.5,
x=5/4,
y=10/9