一道简单的因式分解分解因式:(X+1)(x+2)(X+3)-6*7*8原式=(x+2-1)(X+2)((X+2+1)-(7-1)*7*(7+1)=(X+2)^2-(X+2)-7^3+7(这步是什么原理啊?怎么会相等?)=(X+2-7)[(X+2)^2+7(X+2)+7^2-1](这也解释一下,处学者)=(X-5)(X^2+11X+66)
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一道简单的因式分解分解因式:(X+1)(x+2)(X+3)-6*7*8原式=(x+2-1)(X+2)((X+2+1)-(7-1)*7*(7+1)=(X+2)^2-(X+2)-7^3+7(这步是什么原理啊?怎么会相等?)=(X+2-7)[(X+2)^2+7(X+2)+7^2-1](这也解释一下,处学者)=(X-5)(X^2+11X+66)
一道简单的因式分解
分解因式:(X+1)(x+2)(X+3)-6*7*8
原式=(x+2-1)(X+2)((X+2+1)-(7-1)*7*(7+1)=(X+2)^2-(X+2)-7^3+7(这步是什么原理啊?怎么会相等?)
=(X+2-7)[(X+2)^2+7(X+2)+7^2-1](这也解释一下,处学者)
=(X-5)(X^2+11X+66)
一道简单的因式分解分解因式:(X+1)(x+2)(X+3)-6*7*8原式=(x+2-1)(X+2)((X+2+1)-(7-1)*7*(7+1)=(X+2)^2-(X+2)-7^3+7(这步是什么原理啊?怎么会相等?)=(X+2-7)[(X+2)^2+7(X+2)+7^2-1](这也解释一下,处学者)=(X-5)(X^2+11X+66)
=(x+2-1)((X+2)(X+2+1)-(7-1)*7*(7+1)
=[(x+2-1)(X+2+1)(X+2)-(7-1)*(7+1)*7(这步中将x+2,7看成一个数,用平方差公式)
=[(X+2)^2-1]*(X+2)-(7^2-1)*7
=(X+2)^3-(X+2)-7^3+7
=(X+2-7)[(X+2)^2+7(X+2)+7^2]-(x-5)(相当于a^3-b^3)
=(x-5)[(x+2)²+7(x+2)+7²-1]
= (X-5)(X^2+11X+66)
(x+2-1)(x+2)(x+2+1)-(7-1)*7*(7+1)
=[(x+2)-1][(x+2)+1](x+2)-(7-1)(7+1)*7
=[(x+2)²-1](x+2)-(7²-1)*7
=(x+2)³-(x+2)-7³+7
(x+2)³-(x+2)-7³+7
=[(x+2)³-7³]-(x+2)+7
=[(x+2)-7][(x+2)²+7(x+2)+7²]-(x+2-7)
=(x+2-7)[(x+2)²+7(x+2)+7²-1]
原式=(X+2-1)(X+2)(X+2+1)-(7-1)7(7+1)
=[(X+2)^2-1](X+2)-(7^2-1)7
=(X+2)^3-(X+2)-7^3+7
=(X+2)^3-7^3+7-(X+2)
=(X+2-7)[(X+2)^2+7(X+2)+7^2]-(X+2-7)
=(X-5)(X^2+11X+67)-(X-5)
=(X-5)(X^2+11X+66)