17X+7Y=38 (1)
7X+21Y=76 (2)
将(1)乘以3: 51X+21Y=114 (3)
(3)-(2):44X=38
X=19/22
将X=19/22代入(2)中:21Y=703/22
Y=703/462
所以{X=19/22
Y=703/462
17x+7y=38 7x+21y=76
把x系数变成1,则x+7/17y=38/17 x+3y=76/7,然后相减
x=19/22
y=513/154
X=(38-7y)/17
7[(38-7y)/17]+21y=76
x=19/22
y=513/154
(精锐)