2x+5y=19 3x+2y=12
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2x+5y=193x+2y=122x+5y=193x+2y=122x+5y=193x+2y=12﹛2x+5y=19①3x+2y=12②方法一、由①,得x=19-5y/2③(代入法)把③代入②,得y=3
2x+5y=19 3x+2y=12
2x+5y=19 3x+2y=12
2x+5y=19 3x+2y=12
﹛2x+5y=19 ①
3x+2y=12 ②
方法一、由①,得x=19-5y/2③
(代入法) 把③代入②,得y=3
把y=3代入③,得x=2
所以这个方程组的解是{x=2
y=3
方法二、①×3,得6x+15y=57 ④
(加减消元法)②×2,得6x+4y=24 ⑤
④-⑤消x,得y=3
把y=3代入①,得x=2
所以这个方程组的解是{x=2
y=3
2x+5y=19①
3x+2y=12②
①*3得6x+15y=57③
②*2得6x+4y=24④
③-④得11y=33
y=3
把y=3代入②得
3x=6
x=2
所以
x=2
y=3
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