分解因式(X-1)(X-2)(X+3)(X+2)-60要使用换元法哦.

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分解因式(X-1)(X-2)(X+3)(X+2)-60要使用换元法哦.

分解因式(X-1)(X-2)(X+3)(X+2)-60要使用换元法哦.
分解因式(X-1)(X-2)(X+3)(X+2)-60
要使用换元法哦.

分解因式(X-1)(X-2)(X+3)(X+2)-60要使用换元法哦.
(x-1)(x-2)(x+2)(x+3)-60
=[(x-1)(x+2)][(x-2)(x+3)]-60
=[x^2+x-2][x^2+x-6]-60
=[x^2+x]^2-8[x^2+x]-48
=[x^2+x-12][x^2+x+4]
=(x+4)(x-3)(x^2+x+4)
(x-1)(x-2)(x+2)(x+3)-60
=[(x-1)(x+2)][(x-2)(x+3)]-60
=[x^2+x-2][x^2+x-6]-60
令x^2+x=a
=(a-2)(a-6)-60
=a^2-8a-48
=(a-12)(a+4)
=(x^2+x-12)(x^2+x+4)
=(x+4)(x-3)(x^2+x+4)

原式=
[ (X-1)*(X+2) ] * [(X-2)*(X+3)] -60
=(XX +X -2)* (XX+X -6) -60
令XX+X=T
原式=(T-2)*(T-6)-60
=TT-8T+12-60
=TT-12T-48
=(T-12) * (T + 4)
=(XX +X -12)* (XX + X + 4)
= (X + 4)*(X-3)*(XX +X +4)