Đáp án:
`d)x=17/15`
`e)x=23/3`
Giải thích các bước giải:
`d)(5-3x)²-(3x+1)(3x-1)=-8`
`⇔25-30x+9x²-(9x²-1)=-8`
`⇔25-30x+9x²-9x²+1=-8`
`⇔(9x²-9x²)-30x+(25+1)=-8`
`⇔-30x+26=-8`
`⇔-30x=-8-26`
`⇔-30x=-34`
`⇔x=34/30`
`⇔x=17/15`
Vậy `x=17/15`
`e)(2x-6)²-4(x-6)(6+x)+4=0`
`⇔4x²-24x+36-4(x²-36)+4=0`
`⇔4x²-24x+36-4x²+144+4=0`
`⇔(4x²-4x²)-24x+(36+144+4)=0`
`⇔-24x+184=0`
`⇔-24x=-184`
`⇔x=184/24`
`⇔x=23/3`
Vậy `x=23/3`
