化简:1/(x平方-x)+1/(x平方+x)+1/(x平方+3x+2)+1/(x平方+5x+6)

问题描述:

化简:1/(x平方-x)+1/(x平方+x)+1/(x平方+3x+2)+1/(x平方+5x+6)

原式=1/x(x-1)+1/x(x+1)+1/(x+1)(x+2)+1/(x+2)(x+3)
=1/(x-1)-1/x+1/x-1/(x+1)+1/(x+1)-1/(x+2)+1/(x+2)-1/(x+3)
=1/(x-1)-1/(x+3)
=4/(x²+2x-3)