已知:x=2y+3/3y-2,试用含x的代数式表示y,并证明(3x-2)(3y-2)=13

问题描述:

已知:x=2y+3/3y-2,试用含x的代数式表示y,并证明(3x-2)(3y-2)=13

1.X=(2y+3)/(3y-2)=>X=[(6y-4)/3/(3y-2)]+13/3/(3y-2)
3X=2+13/(3Y-2)=>
3Y-2=13/(3X-2)=>
y=(2X+3)/(3x-2)
2.将x=2y+3/3y-2带入(3x-2)(3y-2)
(3x-2)(3y-2)=3((2y+3)/(3y-2)-2)*(3y-2)=(3(2y+3)-2(3y-2)/(3y-2))*(3y-2)
=3(2y+3)-2(3y-2)=6y+9-6y+4=13