(1) (与式)
)=8-
=(x+1)(x-5)x(x-1)(x-3)+12
={(x²-4x)-5}{(x²-4x)+3} +12
= (x²-4x)² - 20x²--4x) - 15+12
= (x2-4x)2-2(x2-4x)3
-
-
(x² — 4x) + 1}{(x² — 4x) — 3}
1
-
= (x² — 4x + 1)(x² —4x-3)-05
(5)=(x+1)(x+10)X(x+2)(x+9)—180
={(x²+11x)+10}{(x²+11x)+18}- 180
=(x²+11x)²+28(x²+11x)+180-180
2
2
=(x²+11x)²+28(x²+11x)
=(x²+11x)(x²+11x+28)
= x(x+11)(x+4)(x+7)
☐ (1) x²-6x²+1
-XS-X1+