tong cua 2 so la a+b 
hieu la a-b 
tich la ab 
tong gap 7 lan hieu nen: a+b=7(a - b) => a= 4/3b 
tich gap 192 lan hieu nen : ab= 192(a-b) 
thay a=4/3b vao: 4/3b^2=192( 4/3b-b) => 4/3 b^2=64b=>b=0 va b= 48 
voi b=0=> a=0 
voi b=48=> a=64 

Write the sentences with WILL, using the words or prases given

1. my mother/make/a big meal/tonight

=> My mother will make a big meal tonight.

2. I/finish/work/6 p.m

=> I will finish work at 6 p.m

3. I/not have/a birthday party/this year

=> I won't have a birthday party this year.

4. you/meet/Lan/tonight

=> You will meet Lan tonight.

5. we/take/our cousins/holiday/us

=> We will take our cousins on holiday with us.

6. my friends/not come/tonight

=> My friends won't come tonight.

7. he/catch/the train/London/9 o'clock

=> He will catch the train to London at 9 o'clock.

8. I/not come/class/tomorrow

=>I won't come class tomorrow.

9. my garandmother/visit/us/Saturday

=> My garandmother will visit us on Saturday.

10. you/stay/home/this weekend

=> You will stay at home this weekend.

a. I (go) go to sholl by bike.

b. Lisa is (sing) singing now.

c. Minh's friends (be) will be at home Next week.

d. ..Do.. you (speak) speak English?

Trong phản ứng: C u ( O H ) 2 → C u O + H 2 O , nguyên tố đồng:

A. bị oxi hóa

B. bị khử

C. vừa bị oxi hóa, vừa bị khử

D. không bị oxi hóa, cũng không bị khử

How long does the common cold last?