A

250dm2;610dm2;10m2;10000dm2

B

Câu 1 : A

Câu 2 : 10dm2 , 250dm2 , 610dm2 , 10000dm2 

Câu 3 : B

A. 12 tiếng ngày, 12 tiếng đêm ở mọi ngày.

A

A

VD cũng sai ròi kìa -.-

eat - ate

buy - bought

speak - spoke

teach - taught

write - wrote

wear - wore

spend - spent

send - sent

drink - drank

sleep - slept

fall - fell

love - loved

live - lived

go - went

visit - visited

hit - hit

put - put

walk - walked

run - ran

jump - jumped

die - died

miss - missed

Quên không đếm =)) Không đủ thì báo nhé

2 go - went

3 were- are

4 Play-played

5 See- saw

6 Eat- ate

7 Have- had

8 Drink-drunk 

9 sleep-slept

10 read - read

11 Make - made

12 Do - did

13 Take - took 

14 Teach = taught 

15 Come - came 

16 Sing - sang 

17 Get - get 

18 Fall - fell 

19 Sit - sat 

20 lie - lay 

21 rise - rose

a) 72-3x=5x+8

<=>72-3x-5x-8=0

<=>64-8x=0

<=>8x=64

<=>x=8

vậy x=8

b) -4x+(-22)=-18+(-3x)

<=>-4x-22=-18-3x

<=>-4x-22+18+3x=0

<=>-4-x=0

<=>x=-4

vậy x=-4

đúng ko đó

A -3x-5x = 8+72 

-8x=80

x= -10

B -4x+(-22)=-18+(-3x)

-4x+3x=-18+22

-1x=4

x=-4 

:)

Gì mà khó thế mới nó có liên quan tới hai số kia đâu

gợi ý ko có liên quan mk ko giải đc bn ơi!

tổng là 144

Ta có \(\left(x+y\right)^2=xy+3y-1\)

<=>\(x^2+1=-y^2-xy+3y\)

Thế vào phương trình 2 ta có

\(x+y=1+\frac{y}{-y^2-xy+3y}\)

<=> \(x+y=1-\frac{1}{x+y-3}\)

Đặt x+y=a

=> \(a=1-\frac{1}{a-3}\)<=> \(a^2-4a+4=0\)=> a=2

=> x+y=2

Thế vào 1 ta có

\(4=y\left(2-y\right)+3y-1\)=> \(y^2-5y+5=0\)=> \(\orbr{\begin{cases}y=\frac{5+\sqrt{5}}{2}\\y=\frac{5-\sqrt{5}}{2}\end{cases}}\)

Vậy \(\left(x,y\right)=\left(-\frac{1+\sqrt{5}}{2},\frac{5+\sqrt{5}}{2}\right),\left(\frac{-1+\sqrt{5}}{2},\frac{5-\sqrt{5}}{2}\right)\)

`a)3/5+(-4/9)`

`=3/5-4/9`

`=27/45-20/45`

`=7/45`

`b)3/5+2/5 . 15/8`

`=3/5 + 30/40`

`=3/5+3/4`

`=12/20+15/20`

`=27/20`

`c)7/2 . 8/13 + 8/13 . (-5/2)`

`=8/13 . (7/2 +(-5)/2)`

`=8/13 . 1`

`=8/13`

`d)-5/17 . (-9/23)+9/23 . (-22/17) + 11 9/23`

`=-5/17 . (-9/23) + 9/23 . (-1) . 22/17 + 11 + 9/23`

`=-5/17 . (-9/23) + (-9/23) . 22/17+11+9/23`

`= -9/23 ( -5/17 + 22/17)+11+9/23`

`= - 9/23 . 1+11+9/23`

`=-9/23+11+9/23`

`=(-9/23+9/23)+11`

`=0+11`

`=11`

a: =27/45-20/45=7/45

b: =3/5+30/40

=3/5+3/4

=12/20+15/20

=27/20

c: =8/13(7/2-5/2+1)=8/13*2=16/13

d: =9/23*5/17-9/23*22/17+11+9/23

=-9/23+11+9/23

=11

56666666

22 They were born in the village near Tra river where they spent their childhood.

23 He pointed to the stairs which led down to the cellar.

22. They were born in the village near Tra river, where they spent their childhood.

23. He pointed to the stairs, which led down to the cellar.