若x∈[-1,2],y=(1/4)^（x-1/2）-(1/2)^（x-1）+3的取值范围

若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7 若x=-1/4,能否确定代数式(2x-y)(2x+y)+(2x-y)(y-4x)+2y(y-3x)的值? 若x-y=1 化简（x+y)(x^2+y^2)(x^4+y^4)(x^8+y^8)(x^16+y^16) 若x+y=4,则多项式1/2(x+y)+4(x-y)-3（x-y）-3/2(x+y)-x+y值是（） 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 若x*x+y*y=x+y-1/2,求x,y的值如题 若x.y满足x+=4和x-y=2,求xy分之2x-y+1除以-x分之y+y分之x的值 x,y∈R+,1/x+1/y=4,则x+2y最小值? x+y+2(-x-y+1)=3(1-y-x)-4-(y+x-1),x+y=? 若x^5+x^4y+x^4+x+y+1=0,且3x+2y=1,求x,y的值 已知:【(x²+y²)-(x-y)²+2y(x-y)】/4y=1,求4x/4x²-y²-1/2x+y 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 先化简 再求值 (2x-y)(y+x)-(x-2y)(2y+x)-(-3y+x)^2其(√x+1)+y^2+4=-4y 若x,y∈R,(x+y)^2i+6i-x=-y+5(x+y)i-1,求x和y的值 已知x-y=1,求[(x+2y)^2+(2x+y)(x-4y)-3(x+y)(x-y)]除以y的值大神们帮帮忙 已知x-y=1,求[(x+2y)²+(2x+y)(x-4y)-3(x+y)(x-y)]÷y的值 若变量x,y满足约束条件{x>=-1;y>=x;3x+2y