Bài 1:

a) \(\dfrac{-17}{36}\) và \(\dfrac{23}{-48}\) 

\(\dfrac{-17}{36}=\dfrac{-17.4}{36.4}=\dfrac{-68}{144}\) 

\(\dfrac{23}{-48}=\dfrac{-23}{48}=\dfrac{-23.3}{144.3}=\dfrac{-69}{144}\) 

Vì \(\dfrac{-68}{144}>\dfrac{-69}{144}\) nên \(\dfrac{-17}{36}>\dfrac{23}{-48}\) 

b) \(\dfrac{-1}{3}\) và \(\dfrac{2}{5}\) 

Vì \(\dfrac{-1}{3}\) là số âm mà \(\dfrac{2}{5}\) là số dương nên \(\dfrac{-1}{3}< \dfrac{2}{5}\) 

c) \(\dfrac{2}{7}\) và \(\dfrac{5}{4}\) 

Vì \(\dfrac{2}{7}< 1\) mà \(\dfrac{5}{4}>1\) nên \(\dfrac{2}{7}< \dfrac{5}{4}\) 

d) \(\dfrac{267}{-268}\) và \(\dfrac{-1347}{1343}\) 

\(\dfrac{267}{-268}=\dfrac{-267}{268}=\dfrac{-267.449}{268.449}=\dfrac{-119883}{120332}\) 

\(\dfrac{-1347}{1343}=\dfrac{-1347.89}{1343.89}=\dfrac{-119883}{119527}\) 

Vì \(\dfrac{-119883}{120332}>\dfrac{-119883}{119527}\) nên \(\dfrac{267}{-268}>\dfrac{-1347}{1343}\)

Bài 2:

\(\dfrac{5}{2}-\left(1\dfrac{3}{7}-0,4\right)=\dfrac{5}{2}-\dfrac{10}{7}-\dfrac{2}{5}=\dfrac{47}{70}\) 

a) Ta có: \({u_{n + 1}} = 3\left( {n + 1} \right) - 1 = 3n + 2\).

Suy ra \({u_{n + 1}} > {u_n}\).

b) Ta có: \({v_{n + 1}} = \frac{1}{{{{\left( {n + 1} \right)}^2}}}\).

Suy ra: \({u_{n + 1}} < {u_n}\).

\(\left[\frac{1}{3}+(\frac{-1}{2})\right]+\frac{3}{5}=\frac{1}{3}-\frac{1}{2}+\frac{3}{5}=\frac{-1}{6}+\frac{3}{5}=\frac{-5+18}{30}=\frac{13}{30}\)

\(\frac{1}{3}+(\frac{-1}{2}+\frac{3}{5})=\frac{1}{3}+\frac{-5+6}{10}=\frac{1}{3}+\frac{1}{10}=\frac{10+3}{30}=\frac{13}{30}\)

Mà 13 = 13 => \(\frac{13}{30}=\frac{13}{30}\)hay \(\left[\frac{1}{3}+(\frac{-1}{2})\right]+\frac{3}{5}=\frac{1}{3}+(\frac{-1}{2}+\frac{3}{5})\)

3³⁰⁰ > 2³⁰⁰ ( vì 3 > 2 ).

3^200 = (3^2)^100 = 9^100 

2^300 = (2^3)^100 = 8^100 

Vì 9^100 > 8^100 

Vậy 3^200 > 2^300 

Ta có: 1 < 2 ⇒  1  <  2  ⇒ 1 <  2

Suy ra: 1 + 1 <  2  + 1

Vậy 2 <  2  + 1

1. bigger - the biggest

2. hotter - the hottest

3. sweeter - the sweetest 

4. few - the fewest

5. less - thee least

6. more comfortable - the most comfortable

7. more important - the most important

8. expensive - the most expensive

9. better - the best

10. father/further - the farthest/the furthest

1. Mary is taller than her brother.

2. A horse is bigger than a donkey.

3. Our hotel is cheaper than all the others in the town.

4. The Nile is the longest river in the world.

5. Everest is higher than Fansipan.

   1. Mary is taller than her brother

2. A horse is bigger than a donkey

3.our hotel is cheaper than all the others in the town 

4.the Nile is the longest river in the world 

5. Everest is higher than fansipan

1. Mary is taller than her brother

2. A horse is bigger than a donkey

3.our hotel is cheaper than all the others in the town 

4.the Nile is the longest river in the world 

5. Everest is higher than fansipan

a) Vì B 2 ^ , A 1 ^  là cặp góc trong cùng phía nên ta có:

B 2 ^ + A 1 ^ = 180 0 ⇒ A 1 ^ = 180 0 − B 2 ^ = 180 0 − 45 0 = 135 0 .

b) Ta có B ^ 1 = A ^ 1 = 135 ∘  (hai góc đồng vị)

mà A ^ 3 = A ^ 1 = 135 ∘  (hai góc đối đỉnh)

Vậy  B ^ 1 = A ^ 3 = 135 ∘

c) Ta có A ^ 1 + A ^ 2 = 180 ∘ (hai góc kề bù) mà B ^ 1 = A ^ 1  (theo câu b)

Do đó  A ^ 2 + B ^ 1 = 180 ∘

1.

2.

So sánh ngang bằng

​Study well !

1. So sánh hơn nhất:

+ She is the most beautiful student in this class.

+ He is the most intelligent student in this school.

+ This is the cheapest good in this shop.

+ This is the most expensive fan in this shop.

+ That boy is the worst student in this extra class.

2. So sánh ngang bằng (as...as/ the same...as)

*) S + V + as + adjective/adverb + as + O / S + V.

*) S + aux (not) + V + so/as + adjective/adverb +as + O.

*) S + V + as + many/much + N + as + O.

các bạn cố làm cho mình mình sẽ tích cho thật nhiều với các bạn trả lời trước nha.Mai mình phải nộp rồi