\(\sqrt{7-2\sqrt{10}}-\sqrt{7+2\sqrt{10}}\)

\(\sqrt{\left(3-2\sqrt{2}\right)^2}+\sqrt{\left(3+2\sqrt{2}\right)^2}\)

Với giá trị nào của x thì các biểu thức sau có nghĩa

\(\sqrt{X^2-16}\)

\(\sqrt{\dfrac{1}{X-5}}\)
\(\dfrac{x}{X-2}+\sqrt{x-2}\)

Rút gọn biểu thức

a) \(\sqrt{\left(9a\right)}+\sqrt{\left(25a\right)}-\sqrt{\left(49a\right)}\) với a ≥ 0

b) ( 2\(\sqrt{3}\) + \(\sqrt{5}\) ) \(\sqrt{3}-\sqrt{60}\)

Đưa thừa số vào trong dấu căn

a) \(x\sqrt{5}\) với x ≥ 0

b) \(x\sqrt{\dfrac{-29}{x}}\) với x < 0

Đưa các thừa số ra ngoài dấu căn

a) \(\sqrt{4\left(a-3\right)^2}\)với a < 3

b) \(\dfrac{\sqrt{63y^3}}{\sqrt{7y}}\)với y > 0

Write too, too many, too much or enough in the gaps

1. Poor things, they're got ....... free time and they're not eating well ......

2. We don't want to be going replacing furniture every five minutes. It'd just be ........ expensive and I'd go broke!

3. I don't just serve, like, hamburgers and chips. That's not healthy ........

4.I don't do the cooking - Mikey does that 'cos I don't have ........ time

5. Actually, I don't see ........ parents but the odd comment comes back

Write so, such, such a(n) in the gaps in these sentences

1. " We have ..... huge problem of bad eating habits in the United States that teaching about food cannot be left to parents, " she says. " ..... many children generally are eating fast, cheap, easy food that sth has to be done. "

2. Teo has been in the US for only three years, but his teachers say he has learned to speak perfect English in ..... short time because he is ...... happy at school

3. " But eating ..... good food .... makes them care about what they eat.. "

Write so, such, or such a(n) in the gaps in these sentences

1. I always enjoy visiting his house because he makes ........ lovely food

2. There was...... much food on the table that we didn't know where to start

3. I don't think eating pizza at your place is .......... good idea if your parents are at home

4. It's difficult not to cook good food when the ingredients are ........ fresh

5. She's got .... little to say that most people find her rather dull

6. It was .... scray film that I couldn't get to sleep when i went to bed