2y+3x=28 乘3得6y+9x=84(1)
4x+3y=39乘2得6y+8x=78(2)
(1)-(2)得x=84-78=6
代入得y=5
即方程组解为x=6,y=5
2y+3x=28 4x+3y=39
8个回答
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