So qua trung con lai sau khi nguoi thu 3 mua la2x2=4 qua

So qua trung con lai sau khi nguoi thu hai mua la (4+2)x2=12qua

So qua trung con lai sau khi nguoi thu nhat mua(12+2)x2=28qua

So qua trung luc dau la(28+2)x2=60qua

1.this house is big

-> These houses are big.

2. is it your pen ? yes, it is

-> Are they your pens ? -> Yes, they are.

3. is this couch school ? no, it isn't

-> Are these couches school ? No, they aren't.

4. that room isn't small

-> Those rooms aren't small.

5. what 's that ? it 's an eraser

-> What are those ? Those are erasers.

a) \(\frac{x}{10}=\frac{y}{6}=\frac{z}{21}=\frac{x+y+z}{10+6+21}=\frac{5x+y-2z}{50+6-42}=\frac{28}{14}=2\)

-> \(5x=2\cdot50=100\) => \(x=\frac{100}{5}=20\)

\(y=2\cdot6=12\)

\(2z=2\cdot42=84\) => \(z=\frac{84}{2}=42\)

A=|4x-1/4|+2016

Ta có: |4x-1/4|>=0

=>|4x-1/4|+2016>=2016 Hay A>=2016

Nên giá trị nhỏ nhất của A là 2016 khi

4x-1/4=0

4x=0+1/4

4x=1/4

x=1/4:4

x=1/16

Vậy GTNN của A là 2016 khi x=1/16

B=2014-|3x-1/5|

Ta có: |3x-1/5|>=0

2014-|3x-1/5|<=2014 hay B<=2014

Nên GTLN của B là 2014 khi:

3x-1/5=0

3x=0+1/5

3x=1/5

x=1/5:3

x=1/15

Vậy GTNN của B là 2014 khi x=1/15

1.Before John came to the United States , he ( work ) had worked as a clerk.

-> Before + S + QKĐ , S + QKHT

2.Smith ( leave ) left New York last month and ( work ) has been working in Chicago since then.

since then : kể từ đó đến bây giờ : HTHTTD, last month :QKĐ

1. What is this?

-> What are these ?

2. There is a lamp on the table.

-> There are many lamps on the table.

3. It is a couch.

-> They are couches.

4. He is a doctor.

-> They are doctors.

5. That is a bookshelf.

-> Those are bookshelves.