x2-5x+6
用换元法解方程x2-3x+5+6/(x2-3x)
解方程:1/x2+x +1/x2+3x+2 +1/x2+5x+6 +1/x2+7x+12 +1/x2+9x+20=5/x
5x2+4-3x2-5x-2x2-5+6x.
解分式方程:2/x2+5x+6 + 3/x2+x-6=4/x2-4
(x2+5x+6)*(x2+7x+6)-3x2 (因式分解)
1/(x2+3x+2)+1/(x2+5x+6)+1/(x2+7x+12)=1/(x+4)
化简计算~1/(x2-5x+6) - 1/(4x-x2-3) - 1/(3x-x2-2)
解不等式x2-5x+6
计算极限 lim X2-3X+2 -------------- x→2 X2+5X-6
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
x2+5x+6/2+4-x2/4+x2+x-6/3=0 解方程,检验!