用代入消元法解方程组 (1){y=2x-3 3x+2y=1 (2){7x+5y=3 2x-y=-4(3){x-y=5 2x+3y=10 (4){3x-2y=8 y+4x=7
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![用代入消元法解方程组 (1){y=2x-3 3x+2y=1 (2){7x+5y=3 2x-y=-4(3){x-y=5 2x+3y=10 (4){3x-2y=8 y+4x=7](/uploads/image/z/326474-26-4.jpg?t=%E7%94%A8%E4%BB%A3%E5%85%A5%E6%B6%88%E5%85%83%E6%B3%95%E8%A7%A3%E6%96%B9%E7%A8%8B%E7%BB%84+%EF%BC%881%EF%BC%89%7By%3D2x-3+3x%2B2y%3D1+%EF%BC%882%EF%BC%89%EF%BD%9B7x%2B5y%3D3+2x-y%3D-4%EF%BC%883%EF%BC%89%EF%BD%9Bx-y%3D5+2x%2B3y%3D10+%EF%BC%884%EF%BC%89%EF%BD%9B3x-2y%3D8+y%2B4x%3D7)
用代入消元法解方程组 (1){y=2x-3 3x+2y=1 (2){7x+5y=3 2x-y=-4(3){x-y=5 2x+3y=10 (4){3x-2y=8 y+4x=7
用代入消元法解方程组 (1){y=2x-3 3x+2y=1 (2){7x+5y=3 2x-y=-4
(3){x-y=5 2x+3y=10 (4){3x-2y=8 y+4x=7
用代入消元法解方程组 (1){y=2x-3 3x+2y=1 (2){7x+5y=3 2x-y=-4(3){x-y=5 2x+3y=10 (4){3x-2y=8 y+4x=7
(1){y=2x-3 3x+2y=1
y=2x-3 ①
3x+2y=1 ②
①代入②,得3x-6+4x=1,化简求得 x=1
解得x=1,y=-3+2x=-1
(2){7x+5y=3 2x-y=-4
7x+5y=3 ①
2x-y=-4 ②
由①,得y=+3/5-7/5x
代入②,得2x-3/5+7/5x=-4,化简求得 x=-1
解得x=-1,y=0.6-7/5x=2
(3){x-y=5 2x+3y=10
x-y=5 ①
2x+3y=10 ②
由①,得y=-5+x
代入②,得2x-15+3x=10,化简求得 x=5
解得x=5,y=-5+x=0
(4){3x-2y=8 y+4x=7
3x-2y=8 ①
4x+y=7 ②
由①,得y=-4+3/2x
代入②,得4x-4+3/2x=7,化简求得 x=2
解得x=2,y=-4+3/2x=-1
希望能有帮助,o(∩_∩)o
①x=1 y=-1②x=-1 y=2③x=5 y=0④x=2 y=-1
{y=x-5
2x+3(x-5)=10 x=5 y=0
{y=7-4x
3x-2(7-4x)=8 x=2 y= -1