Câu 2: 

a, bạn tự vẽ được nhớ tìm tọa dộ nhé 

x      0       0

y      0       0 

b, Vì tung độ của điểm nằm trên P có hoành độ bằng 8 

=> x = 8

Thay x = 8 vào y = 1/2x^2 ta được : 

\(y=\dfrac{1}{2}.64=32\)

Bài 4: 

a) Ta có: \(B=\dfrac{x^2+\sqrt{x}}{x-\sqrt{x}+1}+1-\dfrac{2x+\sqrt{x}}{\sqrt{x}}\)

\(=\dfrac{\sqrt{x}\left(x\sqrt{x}+1\right)}{x-\sqrt{x}+1}+1-\dfrac{\sqrt{x}\left(2\sqrt{x}+1\right)}{\sqrt{x}}\)

\(=\sqrt{x}\left(\sqrt{x}+1\right)+1-2\sqrt{x}-1\)

\(=x+\sqrt{x}-2\sqrt{x}\)

\(=x-\sqrt{x}\)

\(\frac{x-4}{-5}=\frac{1-2x}{3}\)

Nhân cả 2 vế với 15 ,ta được:

\(\frac{15.\left(x-4\right)}{-5}=\frac{15.\left(1-2x\right)}{3}\)

\(\Leftrightarrow\left(-3\right).\left(x-4\right)=5.\left(1-2x\right)\)

\(\Leftrightarrow-3x+12=5-10x\)

\(\Leftrightarrow-3x+10x=5-12\)

\(\Leftrightarrow7x=-7\)

\(\Leftrightarrow x=-1\)

Vậy x=-1

(𝑥−4)/−5=(1−2𝑥)/3

−15⋅𝑥−4−5=−15⋅−2𝑥+13

−15⋅𝑥−4−5=−15⋅−2𝑥+13

3(𝑥−4)=−5(−2𝑥+1)

3(x-4)=-5(-2x+1)

3(𝑥−4)=−5(−2𝑥+1)

3𝑥−12=−5(−2𝑥+1)

3𝑥−12=−5(−2𝑥+1)

3𝑥−12=10𝑥−5

𝑥 = -1

3 D

4 A

5 A

6 B

7 A

9 D

10 C

2 C

4 A

2 interesting 

Bài II, câu 3 chọn I 

4 - high

5 - ride

6 - put it on

7 - happy

9 - looking

10 - not to smoke

Bài III 

2 - C 

4 - A 

Part 1:

1. with

2. does

3. after

4. if

5. where

6. I won't

Part 2:

1B 2F 3A 4E 5C 6D

Part 3:

1. invited

2. will play

3. have just won

4. be cleaned

5. to take

6. beautifully

7. impression

Part 4:

1. read -> reading

2. disappointing -> disappointed

3. environment -> environmental

4. who -> that

Part 5:

1. the bad weather

2. are made to study

3. were good at learning

4. going to the English

KHO THE

\(A=\frac{\left[\left(25-1\right):1+1\right]\left(25+1\right)}{2}=325.\)

\(B=\frac{\left[\left(51-3\right):2+1\right]\left(51+3\right)}{2}=675\)

\(C=\frac{\left[\left(81-1\right):4+1\right]\left(81+1\right)}{2}=861\)