a) \(\left(x+4\right)^2-\left(x+1\right)\left(x-1\right)=16\)

(x + 4)² - (x + 1) (x - 1) = 16

<=> (x² + 8x + 16) - (x² - 1) = 16

<=> x² + 8x + 16 - x² + 1 = 16

<=> 8x + 17 = 16

<=> 8x = -1

<=> x = 

1.b

2.a

3.c

4.c

P/s : Nhớ tick đúng cho mình nha. Thanks bạn

b) \(\dfrac{2^{15}.9^4}{6^6.8^3}=\dfrac{2^{15}.\left(3^2\right)^4}{\left(3.2\right)^6.\left(2^3\right)^3}=\dfrac{2^{15}.3^8}{3^6.2^6.2^9}=\dfrac{2^{15}.3^8}{3^6.2^{15}}=3^2=9\)

P/s nhớ tick cho mình hết bài nha. Thanks bạn

a) C1:

\(-\left(\dfrac{2}{5}-\dfrac{3}{4}\right)-\left(\dfrac{3}{4}+\dfrac{3}{5}\right)\)= \(-\left(\dfrac{8}{20}-\dfrac{15}{20}\right)-\left(\dfrac{15}{20}+\dfrac{12}{20}\right)\)= \(\dfrac{7}{20}-\dfrac{27}{20}=\dfrac{-20}{20}=-1\)

C2: 

\(-\left(\dfrac{2}{5}-\dfrac{3}{4}\right)-\left(\dfrac{3}{4}+\dfrac{3}{5}\right)\)=\(-\dfrac{2}{5}+\dfrac{3}{4}-\dfrac{3}{4}-\dfrac{3}{5}\)= \(-\dfrac{2}{5}-\dfrac{3}{5}=-\dfrac{5}{5}=-1\)

Chúc chị thi thật tốt nha

Bài 3: 

a) Cho A(x)=0 hay 7x+3=0

Ta có 7x+3=0 => 7x=3 => x=\(\dfrac{3}{7}\)

Vậy nghiệm của đa thức A(x) là \(\dfrac{3}{7}\)

P/s Bài 8,6,7 mình không biết làm vói lại có nhiều câu mình làm sai nhưng nhớ tick cho mình nha 

IV.

1.She's tall and thin

2. He's old

3.It's the short pencil.

4. I like Hip hop music.

5. It's the small house.

6. She has a long hair

7. She has brown eyes.

III.

1.student

2. family

3. short

4.hair; eyes; nose

5. tall

6.beautiful

7. student

8. hair ; round; big

II.

1.is cooking

2. rains

3.are

4.is speaking

5.have

6.plays sports

7.wants; are doing

8.is watching

9. is rainning

10.is