chỉ câu b mk cần gấp cảm ơn
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đây là bài cũ bn ạ, bài này lâu r. ko kiểm tra đâu ạ
46. because
47. for
48. by
49. on
50. on
51. a
52. The
53. -
54. an
55. the
56B leave => left
57A find => finding
58B serious => seriously
59C for => since
1 A great deal of tea is drunk in England
3 Her dog is often taken for a walk by her
4 English is spoken all over the world
5 Their friends have been met at the railway station by a group of students
6 Tom wasn't allowed to take these books home
7 Exercises won't be corrected by the teacher tomorrow
8 How many trees were cut down to built that fence?
9 Many people are attracted by this well-known library
10 He likes being called "sir"
11 My bike can't be repaired by him
12 Tom has been operated by Mary since 10 o'clock
13 We have been taught French by Mr Smith for 2 years
14 The children weren't looked after properly
2:
a: BC=căn 15^2+20^2=25cm
AH=15*20/25=12cm
góc ADH=góc AEH=góc DAE=90 độ
=>ADHE là hình chữ nhật
=>DE=AH=12cm
b: ΔAHB vuông tại H có HD vuông góc AB
nên AD*AB=AH^2
ΔAHC vuông tại H có HE vuông góc AC
nên AE*AC=AH^2
=>AD*AB=AE*AC
c: góc IAC+góc AED
=góc ICA+góc AHD
=góc ACB+góc ABC=90 độ
=>AI vuông góc ED
4:
a: góc BDH=góc BEH=góc DBE=90 độ
=>BDHE là hình chữ nhật
b: BDHE là hình chữ nhật
=>góc BED=góc BHD=góc A
Xét ΔBED và ΔBAC có
góc BED=góc A
góc EBD chung
=>ΔBED đồng dạng với ΔBAC
=>BE/BA=BD/BC
=>BE*BC=BA*BD
c: góc MBC+góc BED
=góc C+góc BHD
=góc C+góc A=90 độ
=>BM vuông góc ED
\(1,=x\left(x^2-2x+1\right)=x\left(x-1\right)^2\\ 2,=6\left(x^2+2xy+y^2\right)=6\left(x+y\right)^2\\ 3,=2y\left(y^2+4y+4\right)=2y\left(y+2\right)^2\\ 4,=2\left(x^2+2x+1-y^2\right)=2\left[\left(x+1\right)^2-y^2\right]\\ =2\left(x+y+1\right)\left(x-y+1\right)\\ 5,=16-\left(x-y\right)^2=\left(4-x+y\right)\left(4+x-y\right)\)