(3x-4y)•(______)=9x2-16y2;5x2-6x+1-(______)=7x+8.
因式分解:(x2+2x+1)-y2=______.
计算:(1)(-7x2-8y2)•(-x2+3y2)=______;(2)(3x-2y)(y-3x)-(2x-y)(3x
已知x2+4x+y2-2y+5=0,则x2+y2=______.
已知实数x、y满足(x2+y2)(x2+y2-1)=2,则x2+y2的值为______.
(选做题)已知x+2y=1,则x2+y2的最小值是______.
若实数x,y满足3x2+2y2=6x,则x2+y2的最大值为______.
已知2x+y=7,x2+y2=5,求(4x+2y)2-3x2-y2+2(1-y2)的值.
在有理数范围内分解因式:(x+y)4+(x2-y2)2+(x-y)4=______.
分解因式(x+y)2+4(x-y)2-4(x2-y2)=______.
若(x+y)2=25,(x-y)2=1,x2+y2的值是______.
已知x+y=4,x2+y2=10,则(x-y)2=______.
已知x-y=5,(x+y)2=49,则x2+y2的值等于______.