44 If I had known your name, I could have introduced you with my friends

45 If the driver in front hadn't stopped so quickly, the accident wouldn't have happened

46 If I had known Geogre wanted to get up early, I would have waken him 

47 If Jim hadn't lent me the money, I wouldn't have been able to buy the motorbike 

48 If she hadn't been wearing the seat belt, she wouldn't have injured (câu này sao ta)

49 If she had had enough money on her, she would have bought the coat

50 If....(tên ai đó) hadn't gone to the bus stop in time, she would have late for the interview

51 If.......hadn't recommened the hotel to us, we wouldn't have stayed at this hotel

52 If you had had breakfast, you wouldn't be hungry now

\(\overrightarrow{u}=4\overrightarrow{MA}-3\left(\overrightarrow{MA}+\overrightarrow{AB}\right)+\overrightarrow{MA}+\overrightarrow{AC}-2\left(\overrightarrow{MA}+\overrightarrow{AD}\right)\)

\(=-3\overrightarrow{AB}+\overrightarrow{AC}-2\overrightarrow{AD}=-3\left(\overrightarrow{AB}+\overrightarrow{AD}\right)+\overrightarrow{AC}+\overrightarrow{AD}\)

\(=-3\overrightarrow{AC}+\overrightarrow{AC}+\overrightarrow{AD}=-2\overrightarrow{AC}+\overrightarrow{AD}\)

\(\overrightarrow{u}^2=\left(-2\overrightarrow{AC}+\overrightarrow{AD}\right)^2=4AC^2-4\overrightarrow{AC}.\overrightarrow{AD}+AD^2\)

\(=4\left(a\sqrt{2}\right)^2-4.a\sqrt{2}.a.cos45^0+a^2=5a^2\)

\(\Rightarrow\left|\overrightarrow{u}\right|=a\sqrt{5}\)

41. Roger: " I don't believe it. " - Anita: " ..................... "

→ Đáp án:                C. Neither do I   

42. Jill : " Do you know Lisa's an excellent pianist ? - Maria: " ..................... "

→ Đáp án:                B. Yes, she does 

43. Karen: " ............... this word in English ? " - Betsy: " C-O-Z-Y "

→ Đáp án:                B. How do you spell    

44. Customer: " I think my change is wrong. " - Shop assistant: " ................... "

→ Đáp án:                C. Sorry. I don't think I have any change  

45. Mandy: " I've got a toothache. " - George: " ................. " 

→ Đáp án:                D. Why don't you see the dentist ? 

Câu 42:

Δ1: VTPT là (m;-1)

Δ2: VTPT là (2;-1)

Để Δ1 vuông góc Δ2 thì m*2+(-1)*(-1)=0

=>2m+1=0

=>m=-1/2

Bài 44:

a, 1,2 : 3,24 = \(\frac{1,2}{3,24}=\frac{120}{324}=\frac{10}{27}\)

b, \(2\frac{1}{5}:\frac{3}{4}=3\frac{41}{45}=\frac{176}{45}\)

c,\(\frac{2}{7}:0,42=\frac{\frac{2}{7}}{0,42}=\frac{2}{7}.\frac{100}{42}=\frac{100}{147}\)

vào đây nè:Chuyên trang lý thuyết tổng hợp các môn THPT bài nào cũng có

44 + 45 + 46 + 47 + 48 + 49 + 50 + 51

= \(\left[\left(51-44\right):1+1\right].\left(\frac{51+44}{2}\right)\)

= \(8.\frac{95}{2}\)

= \(380\)

Vậy 44 + 45 + 46 + 47 + 48 + 49 + 50 + 51 = 380 

giúp mình đi mà!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Xem lại đề.

\(7x-2x=6^{20}:36^9+44:11\)

\(=>x\left(7-2\right)=6^{20}:6^{18}+4\)

\(=>x5=6^2+4=36+4=40\)

\(=>x=40:5\)

\(=>x=8\)

đề đúng rồi á bạn.

https://www.youtube.com/watch?v=vJt-q20BQ9Q link nek

bạn hay xem video bài giảng trong link này nha

https://www.youtube.com/watch?v=wBWTiEHKnqM

lên việt jack và chép cho nhanh