X+1)除以(x+2)加上(x+6)除以(x+7)等于(x+2)除以(x+3)加上(x+5)除以(x+6)求x
问题描述:
X+1)除以(x+2)加上(x+6)除以(x+7)等于(x+2)除以(x+3)加上(x+5)除以(x+6)
求x
答
(X+1)除以(x+2)加上(x+6)除以(x+7)等于(x+2)除以(x+3)加上(x+5)除以(x+6)
[1-1/(x+2)]+[1-1/(x+7)]=[1-1/(x+3)]+[1-1/(x+6)]
1/(x+2)+1/(x+7)=1/(x+3)+1/(x+6)
(2x+9)/(x+2)(x+7)-(2x+9)/(x+3)(x+6)=0
(2x+9)(1/(x+2)(x+7)-1/(x+3)(x+6))=0
(2x+9)[(x^2+9x+18)-(x^2+9x+14)]/(x+2)(x+7)(x+3)(x+6)=0
4(2x+9)/(x+2)(x+7)/(x+3)(x+6)=0
2x+9=0
x=-9/2