x²y²-16xy+64
=(xy-8)²
2分之1x²+xy+2分之1y²
=(1/2)(x²+2xy+y²)
=(1/2)(x+y)²
4分之(x²)-xy+y²
=(1/4)(x²-4xy+4y²)
=(1/4)(x-2y)²
98-28x+2x²
=2(49-14x+x²)
=2(x-7)²
4x³+x-4x²
=x(x²-4x+1)
49-14(x-y)+(x-y)²
=(x-y-7)²
9(2X-Y)-16(+ Y)2
解决方法:原= [3(2X-Y)] 2 - [4 - (X + Y)] 2
= [3 (2X-Y)+4(X +2 Y)] [3(2X-Y)-4(X +2 Y)]
=(6X-1612 +4×+8),(6X-1612 4X-1214)
=(10 +5 Y)(2X-11Y)
= 5(2X + Y)(2X-11Y)