已知x为整数,且(x+3)分之2+(3-x)分之2+(x²-9)分之(2x+18)
问题描述：
已知x为整数,且(x+3)分之2+(3-x)分之2+(x²-9)分之(2x+18)
答
2/(x+3)+2/(3-x)+(2x+18)/(x^2-9)=2/(x+3)-2/(x-3)+(2x+18)/(x^2-9)=2(x-3)/(x^2-9)-2(x+3)/(x^2-9)+(2x+18)/(x^2-9)=(2x-6-2x-6+2x+18)/(x^2-9)=(2x+6)/(x^2-9)=2(x+3)/(x-3)(x+3)=2/(x-3).