若3x2-4x-5=7,则x2-43
若3x2-4x-5=7,则x2-43
1/(x2+3x+2)+1/(x2+5x+6)+1/(x2+7x+12)=1/(x+4)
代数式3x2-4x-5的值为7,则x2-43
x2-5x+1=0则x2+x2/1
1/(x2+x)+1/(x2+3x+2)+1/(x2+5x+6)+1/(x2+7x+12)=4/21
解方程:1/x2+x +1/x2+3x+2 +1/x2+5x+6 +1/x2+7x+12 +1/x2+9x+20=5/x
解分式方程:2/x2+5x+6 + 3/x2+x-6=4/x2-4
5x2—[x2+(4x—x2)—2(x2—3x)]
已知x2+4x-4=0,则3x2+12x-5=______.
若3x2-x=1,则6x3+7x2-5x+2008=______.
若x2+3x-2=0,则x3+5x2+4x+18=______.
若x2-5x+1=0,则x2+x+1x2+1x= ___ .