1. It was lucky that we have => had decided to buy our tickets advance

2. I was pleased to see my old friends last week as we didn't see => haven't seen each other since we finished our course

3.We have to wait for hours at the airport because => because of the bad weather that delayed all the flights

4. We missed our train, so by the time we reached => had reached the theater, the play ended and the audience wasleaving the theater

5. When I came out of the cinema, I had => X found that a thief had taken my car radio

1. My brother and I both have big brown eyes.

=> My brother has the same eyes as me.

2. My favourite subject is Math. Tim likes Math too.

=> Tim likes the same subject as me.

3. I have a problem with exercise. Peter has a problem with it too.

=> Peter has the same problem as me.

4. Louis and james are both 18 years old .

=> Louis is the same age as James.

5.I went to my local primary school. Jim went to my local primary too.

=> Jim went to the same school as me.

5^x-1=5²

=>x-1=2

=>x=3

3^x=9¹⁰

=>3^x=(3²)¹⁰

=>3^x=3²⁰

=>x=20

 2^x=8³

=>2^x=(2³)³

=>2^x=2⁹

=>x=9

2^2x-3=2⁹

=>2x-3=9

=>2x=12

=>X=6

a/ 5^x-1 = 5² => x - 1 = 2 => x = 3

b/ 3^x = 9¹⁰ => 3^x = (3²)¹⁰ => 3^x = 3²⁰ => x = 20

c/ 2^x = 8³ => 2^x = (2³)³ => 2^x = 2⁹ => x = 9

d/ 2^2x-3 = 2⁹ => 2x - 3 = 9 => 2x = 12 => x = 6

5^x-1  = 5^2 

5^x : 5 = 5^2 

5^x = 5^2 * 5

5^x = 5^3

x=3

----------------------------

3^x = 9^10

3^x = (3^2)^10

3^x = 3^20

x=20

--------------------------------

2^x = 8^3 

2^x = (2^3)^3

2^x = 2^9

x=9

-------------------------------

2^2x-3 = 2^9

2^2x : 2^3 = 2^9

2^2x = 2^9 * 2^3

2^2x = 2^12

2x = 12

x=6

Dễ nhận thấy số abc phải khác nhau mà cả abc đều lớn nhất.

Hàng trăm:(xét hàng này theo giá trị từ lớn đến nhỏ thì sẽ tìm được số lớn nhất với lần thử ít nhất)

Nếu hàng trăm là 6 thì hàng đơn vị  b và c đều là 0 mà b;c khác nhau nên a không bằng 6.

Nếu a=5 thì để lớn nhất b=1 và c=0 (chọn)

Nếu a bé hơn 5 thì chắc chắn sẽ không lớn hơn vì khi so sánh ta so hàng lớn nhất(tức hàng trăm trước)

Vậy số cần tìm là 510.

Chúc em học tốt^^

gọi số thứ nhất là a; số thứ 2 là b, ta có:

\(a.b=6210\Rightarrow a=\frac{6210}{b}\)

\(\left(a-7\right).b=5265\)\(\Rightarrow ab-7b=5265\Rightarrow\frac{6210}{b}b-7.b=5265\)

\(\Rightarrow6210-7b=5265\Rightarrow7b=945\)

\(\Rightarrow b=135\)

\(\Rightarrow a=46\)

Vậy \(\orbr{\begin{cases}a=46\\b=135\end{cases}}\)

3ⁿ⁺⁴=3ⁿ.3⁴=3ⁿ.81. suy ra 3ⁿ+1 đồng dư 3ⁿ.81+1 nên nó chia hết 10

ai nhanh mình tích nhưng phải tích lại mình nhé

You are supposed to dressed yourself now.

A. It is time you dressed yourself now.

B. It is supposed that you dress your self.

C. You must dress yourself now.

D. You are going to dress yourself.