4X-3Y-6=0和X平方+Y平方-18X+45=0组成方程组怎么解?5X+12Y+10=0和X平方+Y平方-8X+6Y=0组成方程组又怎么解?

代入法4x-3y-6=0y=(4x-6)/3代入x^2+y^2-18x+45=09x^2+16x^2-48x+36-162x+405=05x^2-42x+81=0(x-3)(5x-27)=0x=3,y=27/5y=(4x-6)/3所以x=3,y=2或x=27/5,y=26/55x+12y+10=0x=(-12y-10)/5x^2+y^2-8x+6y=0144y^2+240y+100...