(X²-X-5)/X+2=(X+2)+1/(X+2)-5是如何化简的来的,

问题描述:

(X²-X-5)/X+2=(X+2)+1/(X+2)-5是如何化简的来的,

(X²-X-5)/X+2)
=[(X²-4)-(X+1)]/X+2)
=(X²-4)/(X+2)-(X+1)/(X+2)
=X-2-(X+2-1)/(X+2)
=X-2-1+1/(X+2)
=X+2-5+1/(X+2)-5
=(X+2)+1/(X+2)-5

(X²-X-5)/(X+2)
=[(x^2+4x+4)-(5x+10)+1]/(x+2)
=[(x+2)^2-5(x+2)+1]/(x+2)
=(x+2)+1/(x+2)-5