Giúp Tui Với, Hứa Sẽ Vote 5S

a)$\frac{1}{2}$ = $\frac{x:8-1}{14}$

=>1.14 = 2(x:8-1)

2(x:8-1)=14

x:8-1=7

x:8=8

x=64

b)$\frac{25}{30}$ =$\frac{2x+3}{6}$ 

=>25.6=30(2x+3)

30(2x+3)=150

2x+3=5

2x=2

x=1

c)$\frac{6}{x-3}$ =$\frac{9}{2x-7}$ 

=>6(2x-7)=9(x-3)

12x-42=9x-27

12x-9x=42-27

3x=15

x=5

d)$\frac{-7}{x+1}$ =$\frac{6}{x+27}$ 

=>-7(x+27)=6(x+1)

-7x-189=6x+6

-7x-6x=189+6

-13x=195

x=-15

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