was thought that the house was broken into last night. 

house was thought to have been broken into last night. 

hotel regulations should be read carefully by the hotel guests. 

languages are spoken in Canada? 

bike was left in the hall this morning.

a: BC=căn 6^2+8^2=10cm

AM=BC/2=5cm

b:

ΔAEH vuông tại A có AI là trung tuyến

nên IH=IA

=>góc IHA=góc IAH

góc IAH+góc MAB

=góc MBA+góc IHA=90 độ

=>góc IAM=90 độ

=>AI vuông góc AM

\(\lim\dfrac{3^n+2.6^n}{6^{n-1}+5.4^n}=\lim\dfrac{6^n\left[\left(\dfrac{3}{6}\right)^n+2\right]}{6^n\left[\dfrac{1}{6}+5\left(\dfrac{4}{6}\right)^n\right]}=\lim\dfrac{\left(\dfrac{3}{6}\right)^n+2}{\dfrac{1}{6}+5\left(\dfrac{4}{6}\right)^n}=\dfrac{0+2}{\dfrac{1}{6}+0}=12\)

\(\lim\left(\sqrt{n^2+9}-n\right)=\lim\dfrac{\left(\sqrt{n^2+9}-n\right)\left(\sqrt{n^2+9}+n\right)}{\sqrt{n^2+9}+n}=\lim\dfrac{9}{\sqrt{n^2+9}+n}\)

\(=\lim\dfrac{n\left(\dfrac{9}{n}\right)}{n\left(\sqrt{1+\dfrac{9}{n^2}}+1\right)}=\lim\dfrac{\dfrac{9}{n}}{\sqrt{1+\dfrac{9}{n^2}}+1}=\dfrac{0}{1+1}=0\)

\(\lim\dfrac{\sqrt{15+9n^2}-3}{5-n}=\lim\dfrac{n\sqrt{\dfrac{15}{n^2}+9}-3}{5-n}=\lim\dfrac{n\left(\sqrt{\dfrac{15}{n^2}+9}-\dfrac{3}{n}\right)}{n\left(\dfrac{5}{n}-1\right)}\)

\(=\lim\dfrac{\sqrt{\dfrac{15}{n^2}+9}-\dfrac{3}{n}}{\dfrac{5}{n}-1}=\dfrac{\sqrt{9}-0}{0-1}=-3\)

x=0 

Ex1

1 usually walks

2 does - usually get

3 rarely washes

4 Do - often visit 

5 isn't often

6 usually walks

7 is occasionally 

8 am hardly

9 are always

10 often washes

Ex2

1 are working

3 are making

3 is having

4 is reading

5 is studying

6 am studying

7 is having

8 aren't studying

9 is having

10 are making

Bài 1: 

a: \(A=\left\{2\right\}\)

b: \(B=\left\{0;4;5\right\}\)

một hôm

Một hôm nhâ

Một hôm nhé 

3.Have you finished your homework yet?

5.I have never donated blood before

tớ biết mỗi 2 câu này thôi