1/（X+9）+1/（X+16）=1/X 求X的解

题目

1/（X+9）+1/（X+16）=1/X 求X的解
连过程一起写出来,以前学的全忘没了,

答案

1/（X+9）+1/（X+16）=1/X
通分分母
=>(X+16)X/(X+9)(X+16)X+(X+9)X/(X+9)(X+16)X=(X+9)(X+16)/(X+9)(X+16)X
等号左右消分母
=>(X+16)X+(X+9)X=(X+9)(X+16)
=>XX+16X+XX+9X=XX+25X+144
=>XX=144
=>X=12或-12