Lời giải:
`1)`
`3x(12x-4)-(6x-3)^2=30`
`⇔36x^(2)-12x-[(6x)^(2)-2.6x.3+3^2]=30`
`⇔36x^(2)-12x-36x^(2)+36x-9-30=0`
`⇔(36x^(2)-36x^2)+(-12x+36x)+(-9-30)=0`
`⇔24x-39=0`
`⇔24x=39`
`⇔x=39/24=13/8`
Vậy `x=13/8`
`2)`
`2x(5-2x)+2x(x-1)=15-2(1+x)(x-1)`
`⇔10x-4x^(2)+2x^(2)-2x=15-2(x^(2)-1)`
`⇔-2x^(2)+8x-15+2x^(2)-2=0`
`⇔8x-17=0`
`⇔8x=17`
`⇔x=17/8`
Vậy `x=17/8`
`3)`
`3(2x-1)-5(x-3)=24-15x`
`⇔6x-3-5x+15=24-15x`
`⇔x+15x=24-12`
`⇔16x=12`
`⇔x=12/16=3/4`
Vậy `x=3/4`
`4)`
`2x^(2)+3(x-1)^2=5x(x+1)`
`⇔2x^(2)+3(x^(2)-2x+1)=5x^(2)+5x`
`⇔5x^(2)-6x+3-5x^(2)-5x=0`
`⇔-11x=-3`
`⇔x=3/11`
Vậy `x=3/11`
