(X+2)/(X+1)-(X+4)/(X+3)=(X+6)/(X+5)-(X+8)/(X+7)
问题描述:
(X+2)/(X+1)-(X+4)/(X+3)=(X+6)/(X+5)-(X+8)/(X+7)
答
(X+2)/(X+1)-(X+4)/(X+3)=(X+6)/(X+5)-(X+8)/(X+7) (X+1+1)/(X+1)-(X+3+1)/(X+3)=(X+5+1)/(X+5)-(X+7+1)/(X+7) 1/(x+1)-1/(x+3)=1/(x+5)-1/(x+7) (x+5)(x+7)=(x+1)(x+3) x^2+12x+35=x^2+4x+3 8x=-32 x=-4