b)\(x\left(2x+1\right)-x^2\left(x+2\right)+x^3-x+3\\=2x^2+x-x^3-2x^2+x^3+-x+3=3\\ Vậygtbttrênkophụthuộcvàogtcủabiến.\)

a)\(x\left(x^2+x+1\right)\)\(-\)\(x^2\left(x+1\right)-x+5\)

=\(x^3+x^2+x-x^3-x^2-x+5=5\)

Vậy gtbt trên ko phụ thuộc vào gt của biến.

10. \(\left|17+\left(x-15\right)\right|\)<5

\(\left|2+x\right|< 5\)

+)2+x<5\(\Rightarrow\)x=3

+)2+x<-5\(\Rightarrow\)x=-7.

6. \(\left|x\right|\)-3+6=16

\(\left|x\right|\)=13

\(\Rightarrow\)x=13 hoặc x=-13.

7. 35-\(\left|2x-1\right|\)=14

\(\left|2x-1\right|\)=21

+)2x-1=21

x=11.

+)2x-1=-21

x=-10.

8. \(\left|3x-2\right|+5=9-x\)

\(\left|3x-2\right|=4-x\)

+)3x-2=4-x

4x=6\(\Rightarrow\)x=\(\dfrac{3}{2}\).

+)3x-2=-(4-x)

3x-2=-4+x

2x=-2\(\Rightarrow\)x=-1.

9. x-(-25+7)>12-(15-14)

x+18>11

x>-7.

1.x-43=(35-x)-48 4. -(35-x) -(37-x)=33-x

x-43=-13-x -35+x-37+x=33-x

2x=30 -72+2x=33-x

x=15. 3x=105

2. 305-x+14=48+(x-23) x=35.

319-x=25+x 3. -(x-6+85)=(x+51)-54

-2x=-294 -x+6-85=x-3

x=147. -x-79=x-3

5.13-\(\left|x\right|\)=\(\left|-4\right|\) -2x=76

13-\(\left|x\right|\)=4 x=-38

\(\left|x\right|\)=9

\(\Rightarrow\)x=9 hoặc x=-9.

b

Read the following passage and choose the best answers.

Question 5

A. many

B. much

C. more

D. lots