就一个填空!若5^x=3,5^y=2,则5^x-2y=_____________.
就一个填空!若5^x=3,5^y=2,则5^x-2y=_____________.
已知x-2y=2,则代数(x-2y)的平方-2x+4y-5的值为_____________
1.抛物线y=2x^2+5x-3与x轴的交点坐标是_____________
1、若有理数x、y满足|4-2x|+(y-3x)平方=0,则代数式x平方-2xy+y平方的值为_____________
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
若3x-5y=0,则x+y/x=(),x-y/y=(),2x-3y/2x+3y=( )
填空-5/7x=( )/7x=5/( ) x-y/x+y=X^2-y^2/( )
先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y
若5x+3y=3x+4y=x+2y+6,则x+y=___
若x/y=4/3 则3x+2y/2x-5y=
6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27