x=(x¹-2x²+1)-4x² = (x²-1)²-(2x)²
= {(x²-1)+2x}{(x²-1)-2x}
= (x²+2x-1)(x² - 2x-1)
(3) = (x¹-2x²y²+y¹)-16x²y²
= (x² - y²)²-(4xy)²
= {(x² - y²) + 4xy}{(x² - y²)-4xy}
= (x² + 4xy-y²)(x² - 4xy-y²)
(4) =(x¹+4x²y² +4y¹)-4x²y²
= (x²+2y²)²-(2xy)²
= {(x²+2y²)+2xy){(x²+2y²)-2xy)
=(x²+2xy+2y²)(x²-2xy + 2y²)
=X6
38 (1) = (x³)² +7x³-8=(x³− 1)(x³ +8)
= (x− 1)(x²+x+1)(x+2)(x²-2x+4)
=(x-1)(x+2)(x²+x+1)(x²-2x+4)
(2) 与式=(x^2-(y3)2 = (x3+y^)(x3-y3)
= (x+yXx² - xy + y²)(x−y)(x² + xy + y²)
= (x+yXx-y\x² - xy + y²)(x² + xy + y²)
[参考x-y=(x2)3-(y^2)3 に着目して,次のよう
= (x+2)(x
与式=(x-4x)-
= x(x²-4)-
=(x-5)(x²
=(x-5)(x
(2) 与式= (8x3+1)+
= (2x+1)(4x
= (2x+1){(4
= (2x+1)(4
(3) 与式= (xy-x2
= x²(y-2)
=(x²-4y
= (x+2y)
[参考] 次数の低い
与式= (4y2-x 2
=(4y²-x²
=(x²-4y²
= (x+2y)(
(4) 与式= (a2+
=(a²+
別解
