$#Dinosaurss$
a, `3x(x-11)=2x(x-8)`
`⇔3x²-33x=2x²-16x`
`⇔3x²-33x-2x²+16x=0`
`⇔x²-17x=0`
`⇔x(x-17)=0`
`⇔x=0`
`x-17=0`
`⇔x=0`
`x=17`
Vậy `S={0;17}`
b, `(x-3)²=(x-7)²`
`⇔x²-6x+9=x²-14x+49`
`⇔x²-6x+9-x²+14x-49=0`
`⇔8x-40=0`
`⇔8x=40`
`⇔x=5`
Vậy pt có nghiệm duy nhất là `x=5`
c, `(2x-3)²=(x-7)²`
`⇔(2x-3)²-(x-7)²=0`
`⇔(2x-3-x+7)(2x-3+x-7)=0`
`⇔(x+4)(3x-10)=0`
`⇔x+4=0`
`3x-10=0`
`⇔x=-4`
`x=10/3`
Vậy `S={-4;10/3}`
d, `(x-1)(x+3)=(x+3)(2x-8)`
`⇔(x-1)(x+3)-(x+3)(2x-8)=0`
`⇔(x+3)(x-1-2x+8)=0`
`⇔(x+3)(-x+7)=0`
`⇔x+3=0`
`-x+7=0`
`⇔x=-3`
`x=7`
Vậy `S={-3;7}`
e, `(x+2)(x-5)=(3x-2)(3x-15)`
`⇔(x+2)(x-5)-(3x-2).3.(x-5)=0`
`⇔(x-5)(x+2-9x+6)=0`
`⇔(x-5)(-8x+8)=0`
`⇔x-5=0`
`-8x+8=0`
`⇔x=-5`
`x=1`
Vậy `S={-5;1}`
@DuongQuynhChi<3
