câu 1:
a) -5x+6=0
=> -5x=-6
=> x=6/5
vậy S={6/5}
b) 2(x-4)(x+3)=0
=> (x-4)(x+3)=0
=> x-4=0 hoặc x+3=0
=> x=4 hoặc x=-3
vậy S={-3,4}
c) $\frac{5(1-2x)}{3}$ +$\frac{x}{2}$ =$\frac{3(x-5)}{4}$ -2
=> 20(1-2x)+6x=9(x-5)-24
=> 20-40x+6x=9x-45-24
=> 20-34x=9x-69
=> 43x=89
=> x= 89/43
vậy S={89/63}
d) $\frac{3}{x-1}$ =$\frac{3x+2}{1-x^{2}}$ -$\frac{4}{x+1}$
=> 3(x+1)=-3x-2-4(x-1)
=> 3x+3=-3x-2-4x+4
=> 10x=-1
=> x=-1/10
vậy S={-1/10}