已知x-2y=3,2x^2-8y^2=5,则x+2y=

来源：学生作业帮助网编辑：六六作业网时间：2024/11/29 10:43:51

已知x-2y=3,2x^2-8y^2=5,则x+2y=已知x-2y=3,2x^2-8y^2=5,则x+2y=已知x-2y=3,2x^2-8y^2=5,则x+2y=2x²-8y²=2

已知x-2y=3,2x^2-8y^2=5,则x+2y=
已知x-2y=3,2x^2-8y^2=5,则x+2y=

已知x-2y=3,2x^2-8y^2=5,则x+2y=
2x²-8y²
=2(x+2y)(x-2y)=5
所以x+2y=5/[2(x-2y)=5/6

2x^2-8y^2=2（x^2-4y^2）=2（x-2y）（x+2y）=5
又
x-2y=3
则
6（x+2y)=5
x+2y=5\6

2x^2-8y^2=5
2（x^2-4y^2）=5
（x+2y）（x-2y）=5/2
（x+2y）=（5/2）/（x-2y）=（5/20)/3=5/6

2（x∧2-4y∧2）=2（x-2y）（x+2y）=5，2×3×（x+2y）=5，
x+2y=5／6

已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值已知3x =2y 求x/x+y+y/x-y-y²/x²-y² 已知x-2y=2016,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]除以8x的值已知x-2y=2012,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]/(8x)) 已知x-2y=2010,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]÷8x的值已知:x-2y=2009,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]除以8x 的值已知|x|=2,|y|=3,|x+y|=-(x+y)求x-y 已知实数x.y满足根号(x+y-8)+根号(8-x-y)=根号(3x-y-4)+根号(x-2y+7),求x,y 已知xy/x+y=2,则代数式3x-5y+8y/-x+3xy-y的值已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. 已知2y-x=-3,求[4y(2x-y)-2x(2x-y)]/(2x-y 已知X*X+Y*Y+6X-8Y+25=0 求（Y/X)+(X/Y)-2=? 已知x*x+4x+y*y-2y+5=0,则x*x+y*y=? 已知x-y=3,x+y=8,问x^2 -y^2=? 已知x-2y=2,求4x-y-8分之3x+y-6 已知2x-y=-3,求代数式5(x-3y)-2(x-7y) 已知x-y=3则5(x-y)-3x+3y-2=