Tam giác ABC vuông tại A, biết sin B = 0,4. Khi đó giá trị của cos B là

Điều kiện để $\sqrt{2x-4}+\sqrt{3-x}$ có nghĩa 

Hoà tan hoàn toàn 7,8g hỗn hợp Mg và Al vào dung dịch HCl thì thu được 8,96 lít khí hidro (đktc) 

a) Tính % khối lượng mỗi kim loại trong hỗn hợp . 

b) Khi cô cạn dung dịch sau phản ứng thu được bao nhiêu gam muối 

2 Put the letters in order to make activities and complete the sentences.
1 Cameron has always got his (rinrtaes) in his bag so he can play basketball.
2 My mother likes to (wdra reupctis) of people and comic characters when she has free time.
3 My friend and I (neslit ot ngsos) together on my tablet. We both like the same music.
4 We always wear (stmeleh) when we go skateboarding.
5 I like (tblea nnsite). It’s a fast and lively sport.
6 I love (artliam rtsa), like karate and judo.

1 Choose the correct options to complete the sentences.
1 Lucy’s wife / husband / parents is a teacher. The children really like him.
2 I start / go / get school at 8.55 am every day.
3 My grandmother is short / straight / long and has got long, grey hair.
4 Tina’s uncle / aunt / son is my mother. Tina and I are cousins.
5 We usually do our homework / wake up / go to bed when we get home from school.
6 Dave’s sister has long / tall / blue hair and brown eyes.

Tìm x nguyên để giá trị của biểu thức $M=\frac{\sqrt{x }+1}{\sqrt{x}-1}$là số nguyên.