{[2x/(x-3)]-[x/(x+3)]}*(x²-9)/x 再随便代入一个整数求值

题目

{[2x/(x-3)]-[x/(x+3)]}*(x²-9)/x 再随便代入一个整数求值

答案

{[2x/(x-3)]-[x/(x+3)]}*(x²-9)/x
=[2x/(x-3)]*[(x²-9)/x]-[ x/(x+3)]}*[(x²-9)/x ]
=2(x+3)-(x-3)
=x+9
当x=1时
原式=1+9=10