(x2+3x+12)(x2+7x+12)-120
(x2+3x+12)(x2+7x+12)-120
解方程:1/x2+x +1/x2+3x+2 +1/x2+5x+6 +1/x2+7x+12 +1/x2+9x+20=5/x
初中因式分解 (x2+3x+2)*(x2+7x+12)-120
因式分解(x2-x)(x2-x-8)+12
1/(x2+3x+2)+1/(x2+5x+6)+1/(x2+7x+12)=1/(x+4)
(x2-3)(x2-2)-2十字相乘法做 (x2+3x+2)(x2+7x+12)-24十字相乘法做
3x2-[7x-(4x-3)-2x2]
(x2+5x+2)(x2+5x+3)-12怎么因式分解 (x2)是x的平方,
先化解,再求值:【1/(x2+3x+2)+1/(x2+5x+6)+1/(x2+7x+12)】/1/(x2+9x+20),
1/(x2+x)+1/(x2+3x+2)+1/(x2+5x+6)+1/(x2+7x+12)=4/21
先化简,再求值:5x2-[3x-2(2x-3)+7x2],其中x=12
解方程7/(x+x2)-3/(x-x2)=6/(x2-1)