Giải thích các bước giải:
`a,(x+1)/3-(7-3x)/2=16`
`⇔2(x+1)-3(7-3)=96`
`⇔2x+2-21+9x=96`
`⇔11x=115`
`⇔x=115/11`
`b,(2x-7)^2-6(2x-7)(x-3)=0`
`⇔4x²-28x+49-6(2x²-6x-7x+21)=0`
` ⇔4x²-28x+49-12x²+36x+42x-126=0`
`⇔-8x²+50x-77=0` `⇔8x²-50x+77=0`
`⇔x= 7/2`hoặc `x=11/4`
`c,(x+5)/(x-5)-(x-5)/(x+5)=20/(x^2-25)``Đkxđ:....`
`=>(x+5)^2-(x-5)^2=20` `<=>20x=20`
`<=>x=1`
Vậy `x=1`
