3. Tìm x, y, z biết: \(\frac{x^3}{8}=\frac{y^3}{64}=\frac{z^3}{216}\) và x² + y² +z² =14

2. Tìm a, b,c biết 2a = 3b, 5b = 7c và 3a - 7b + 5c = -30

1. tìm x, y,z biết:

a. \(\frac{x}{y}=\frac{7}{20},\frac{y}{z}=\frac{5}{8}\) và 2x + 5y - 2z = 100

b. 5x = 8y = 20z và x - y - z = 3

c. \(\frac{6}{17}x=\frac{9}{2}y=\frac{18}{5}z\) và -x + y + z = -120

d. \(\frac{x}{2}=\frac{y}{3},\frac{y}{5}=\frac{z}{6}\) và x - y + z= -49

Put the verbs in the brackets into the correct form:

1. If you (send)____ this letter now, she (receive)____ it tomorrow.

2. Kate (go)____ shopping if she (have)____ time in the afternoon.

3. She (spend)_____ a year in the USA if it (be)____ easier to get a green card.

4. If her boyfriend (phone/not)______ today,she (leave)______him.

5. If you (go)_____ by bike more often, you (be/not)______ so flabby.

6. If he (have)_____ more time, he (earn)______ karate.

Chuyển câu chủ động sang câu bị động:

1. My mother gives me 10.000 VND every day.

2. Mr. Brown bought a new house in this city two years ago.

3. They built a new bridge in this village.

4. She shows the tickets to the airline agent.

5. They keep this room clean all the time.

6. Someone took some of my books away.

7. they usually use this room at weekend.

8. they finished their project a week ago.

9. she usually pays me after 2 days.

7. Put the verbs in brackets into the correct form of conditional sentence type 1:

1. If people (pollute) _______the environment, a lot of animals (die) _____.

2. If water (consist)______ germs, people (get)_____ ill.

3. If the poles (melt)_____, huge landmasses (be)____ underwater.

4. Many precious animals (disappear)_____, if people (cut down)______trees.

5. If nuclear waste (throw)______ away, it (be)______ very dangerous.

6. If the emission of CO₂ (continue)_____ at high rate, the climate (destroy)________.

7. We (save)_____ the trees if we (save) ______ paper.

8. If schools (teach)______ about environmental problems, all students (know)_____ how to protect the environment.

9. if more people (travel)_______ by bike or bus, we (not have)____ traffic jam.

10. if the government (fine)_______ heavily to the factories, they (not dump)____ sewage into the ocean.

1. Chuyển sang câu bị động:

1. People grow rice in tropical countries.

2. Viet Nam exports a lot of rice to China.

3. They built that bridge many years ago.

4. Peter invited me to his party 2 days ago.

5. I met him at the airport last week.