用代入法解:{3x-5y=9,2x+3y=-6
用代入法解方程组5x+3y=36,-x+9y=2
用代入法解方程组:y=3(x-y),x=2(x-y)
用代入法解方程组2x+3y=12,3x-4y=17代入法代入法代入法!
1.用代入法解:(1)3x-5y=-9 (2)2x+7y=-6
用代入法解方程组:3x-5y=-9,2x+7y=-6
y=x+3 7x+5y=9用代入法解方程
用代入法解 3x+4y=16 5x-6y=33
3x+4y=2,2x-y=5用代入法解
{2x+5y=-2,x=8-3y用代入法解方程组
用代入法解方程组x-y=-6,2x+3y=8.
用代入法解方程组:2x+3y=-1 4x-y=5
2x+y=5 4x+3y=11 用整体代入法解