\(a,=\dfrac{3\left(2x-1\right)}{x}\cdot\dfrac{3x^2}{\left(2x-1\right)\left(2x+1\right)}=\dfrac{9x}{2x+1}\\ b,=\left[\dfrac{x}{y\left(2y-x\right)}+\dfrac{4y}{x\left(x-2y\right)}\right]\cdot\dfrac{2y-x}{y}\\ =\dfrac{4y^2-x^2}{xy\left(x-2y\right)}\cdot\dfrac{2y-x}{y}=\dfrac{x^2-4y^2}{xy^2}\)

lỗi

lỗi thiệt

  giúp ae ơi

1 is bigger than mine

2 the tallest student in my class

3 speaks English better than Mum

4 cook as well as lan

5 the best in the city

6 is better than this one

7 is a more careful writer than she is

8 drives more carefully than Peter

1. Your kitchen is bigger than mine

2. Dave is the tallest person in the class

3. Dad speaks English better than Mum

4. Hoa can't cook as well as Lan

5. This restaurant ts the best one in the city

6. That watch is better than this one

7. My sister doesn't write more carelessly than she did

8. Tom drives more carefully than Peter

Câu 7 ko chắc đâu nha

1. didn’t use to be

2.used to write

3. used to play

4. didn’t use to travel

5. used to walk

6. didn’t use to swim

7. used to watch

8. used to climb

9. didn’t use to buy

10. used to shop

a: Ta có: \(2\sqrt{28}+3\sqrt{63}-3\sqrt{\dfrac{112}{9}}-\sqrt{\dfrac{196}{7}}\)

\(=4\sqrt{7}+9\sqrt{7}-4\sqrt{7}-2\sqrt{7}\)

\(=7\sqrt{7}\)

b: Ta có: \(\sqrt{8+2\sqrt{7}}-\sqrt{12-\sqrt{140}}-\sqrt{5}\)

\(=\sqrt{7}+1-\sqrt{7}+\sqrt{5}-\sqrt{5}\)

=1

đâu bạn???
 

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