\(320.15\%=48\)

\(320.\dfrac{15}{100}=48\)

là 48 

\(2.\left(70-x\right)+2^3.3^2=92\)

\(140-2x+72=92\)

\(-2x=92-212\)

\(-2x=-120\)

\(x=60\)

mỗi người 1 câu trả lời thì ai đúng v ạ 

c: \(\Leftrightarrow x+7=38\)

hay x=31

15-(2x-3)=6                        (x-2).3=3²

⇔   2x-3=9                      ⇔(x-2).3=9

  ⇔  2x=12                      ⇔x-2=3

    ⇔   x=6                         ⇔x=5

(x+7)-25=13                  450:(x-19)=50

⇔x+7=38                       ⇔x-19=9

⇔x=31                             ⇔x=28

`@` `\text {Ans}`

`\downarrow`

`a)`

`4x = 320 \div 16`

`=> 4x = 20`

`=> x = 20 \div 4`

`=> x=5`

Vậy, `x=5`

`b)`

`(x-10) \div 5 = 2`

`=> x - 10 = 2*5`

`=> x - 10 = 10`

`=> x = 10 + 10`

`=> x=20`

Vậy, `x=20`

`c)`

`(20+x) \div 5 = 25`

`=> 20+x = 25*5`

`=> 20+x = 125`

`=> x = 125 - 20`

`=> x = 105`

Vậy, `x=105.`

`@` `\text {Kaizuu lv uuu}`

A=1/2^2+1/3^2+...+1/10^2

=>A<1-1/2+1/2-1/3+...+1/9-1/10=1-1/10<1

a) x = 21

b) x = 30

1 would you have done

2 rains

3 wouldn't have married

4 would have to

5 had known

6 will never pass

7 would catch

8 would have had

9 would have got

10 tries

11 had lost

12 wouldn't have gone

13 doesn't he come

14 wouldn't have come

15 had been

16 isn't 

17 is

18 had been

19 fell

20 could help

21 had come - would have met

22 would buy - had

23 bought - wouldn't look

24 had known - would have met

25 wouldn't have gone - had asked