`#Sad`
`a)`
`5x+(1)/(5)x-2+36-(1)/(3)x = 12`
`⇔ (5x+(1)/(5)x-(1)/(3)x)+(-2+36) = 12`
`⇔ (73)/(15)x+34 = 12`
`⇔ (73)/(15)x = -22`
`⇔ x = -(330)/(73)`
`\text{Vậy S=}` `{-(330)/(73)}`
`b)`
`7x(x-2)-5(x-1) = 7x^2+3`
`⇔ 7x^2-14x-5x+5-7x^2-3 = 0`
`⇔ (7x^2-7x^2)+(-14-5x)+(5-3) = 0`
`⇔ -19x+2 = 0`
`⇔ -19x = -2`
`⇔ x = 2/(19)`
`\text{Vậy S=}` `{2/(19)}`
`c)`
`2(5x-8)-3(4x-5) = 4(3x-4)+11`
`⇔ 10x-16-12x+15 = 12x-16+11`
`⇔ -2x-1 = 12x-5`
`⇔ -2x-12x = 1-5`
`⇔ -14x = -4`
`⇔ x = 4/(14)`
`\text{Vậy S=}` `{4/(14)}`