## Giúp mình vs,thanks ạ

Question

Giúp mình vs,thanks ạ

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4 years 2020-10-19T14:15:22+00:00 2 Answers 67 views 0

1. Bài 1:

a) x/4=5/2

⇒ 2x=4.5=20

⇒ x=10

b) (1/2)/x =(3/4)/(2/3)

⇒ 3/4x=1/2 .2/3

⇒ 3/4x=1/3

⇒ x=4/9

c) x/2=8/x

⇒ x²=8.2=16

⇒ x=±4

Bài 2:

-3/12=-30/120

(-3)/(-30)=12/120

120/12=(-30)/(-3)

120/(-30)=12/(-3)

2. Bạn tham khảo!
Bài 1
$a)$ $\dfrac{x}{4}$ $=$ $\dfrac{5}{2}$
$→$ $x$ $.$ $2$ $=$ $4$ $.$ $5$
$→$ $x$ $.$ $2$ $=$ $20$
$→$ $x$ $=$ $20$ $:$ $2$
$→$ $x$ $=$ $10$
$b)$ $1/2/x$ $=$ $3/4/2/3$
$→$ $\dfrac{0.5}{x}$ $=$ $\dfrac{0.75}{0.67}$
$→$ $x$ $.$ $0.75$ $=$ $0.5$ $.$ $0.67$
$→$ $x$ $.$ $0.75$ $=$ $\dfrac{67}{200}$
$→$ $x$ $=$ $\dfrac{67}{200}$ $:$ $0.75$
$→$ $x$ $=$ $\dfrac{67}{150}$
$c)$ $\dfrac{x}{2}$ $=$ $\dfrac{8}{x}$
$→$ $x$ $.$ $x$ $=$ $2$ $.$ $8$
$→$ $2x$ $=$ $16$
$→$ $x$ $=$ $16$ $:$ $2$
$→$ $x$ $=$ $4$ và $x$ $=$ $-4$
Bài 2
$-3$ $.$ $420$ $=$ $12$ $.$ $-30$
$→$ $\dfrac{-3}{12}$ $=$ $\dfrac{420}{-30}$
$→$ $\dfrac{12}{-3}$ $=$ $\dfrac{-30}{420}$
$→$ $\dfrac{12}{-30}$ $=$ $\dfrac{-3}{420}$
$→$ $\dfrac{-30}{12}$ $=$ $\dfrac{420}{-3}$
$FbBinhne2k88$