I

9 A

10 B

12 C

14 B

16 B

19 A

20 A

21 D

22 B

23 F

24 T

25 T

26 T

27 B

28 A

29 competitions

30 traditional

31 peaceful

32 noise

33 entertainment

34 walking

35 There is a lot of room for people to play in my city

36 I have to use public transportation because I don't have a vehicle everyday

37 Her hobbies are painting and hanging out with her friends on the weekend

38 There aren't many bookstores in their town

39 It took him two months to build Eiffel Tower model

40 It's important to practice your English everyday

dấu <=> đầu tiên = x²-2x+2x-4

phần quy đồng bn sai á

Bài `13`

\(a,\sqrt{27}+\sqrt{48}-\sqrt{108}-\sqrt{12}\\ =\sqrt{9\cdot3}+\sqrt{16\cdot3}-\sqrt{36\cdot3}-\sqrt{4\cdot3}\\ =3\sqrt{3}+4\sqrt{3}-6\sqrt{3}-2\sqrt{3}\\ =\left(3+4-6-2\right)\sqrt{3}\\ =-\sqrt{3}\\ b,\left(\sqrt{28}+\sqrt{12}-\sqrt{7}\right)\cdot\sqrt{7}+\sqrt{84}\\ =\left(\sqrt{4\cdot7}+\sqrt{4\cdot3}-\sqrt{7}\right)\cdot\sqrt{7}+\sqrt{4\cdot21}\\ =\left(2\sqrt{7}+2\sqrt{3}-\sqrt{7}\right)\cdot\sqrt{7}+2\sqrt{21}\\ =2\cdot7+2\sqrt{21}-7+2\sqrt{21}\\ =14+2\sqrt{21}-7+2\sqrt{21}\\ =7+4\sqrt{21}\)

giải hết giùm em luôn được không ạ, em cảm ơn.

54 + 34 = 88

A. 34 + 67= 101

B. 67 + 23 = 90

54+34=88

34+67=101

67+23=90

1 chữ số

@Bảo

#Cafe

số có 1 chữ số

\(\frac{3}{5}\)+ \(\frac{5}{6}\)=\(\frac{18}{30}\)+ \(\frac{25}{30}\)=\(\frac{43}{30}\)

bài này đề sai và bạn kia làm cũng sai rồi

Ta có: 4x^3=4x

Suy ra: 4x^3-4x=0

Suy ra: 4x(x^2-1)=0

Suy ra: 4x=0 nên x=0

            x^2-1=0 nên x^2=1 nên x=1 hoặc -1

KL: x thuộc {1;-1;0}