The second question:

The third question:

The fourth question:

y 1=ax

y2*x=b

Replace two values of x

4=y=a+b

5=2a+b/2

The solution is a=2 and b=2.

So y = 2x+2/x.

When x=-2 and y=-5.

The fifth question:

The area of surface A is 18, the area of surface B is 6, and the mass of the object is constant, so the pressure is inversely proportional to the area, so the pressure is 3 m.

The sixth question:

When the distance from point P to point B or point C is 1.75, the requirements are met.

So the exercise time is 7 seconds or 25 seconds.

Question 7:

y 1*3x=a

y2=-bx

Substitute two corresponding values of x and y given.

The solution is a =-8 and b =- 1.

So y =-8/(3x)+x.

Question 8:

Because it is a parallelogram.

So AD=BC angle A= angle C.

And because DF and be are angular bisectors.

So angle ADF= angle CBE

So the triangle ADF is equal to the triangle CBE.

So AF=CE

Question 9:

AD is perpendicular to AD at point h through the vertical line at point p.

It is easy to prove that triangle AGP is equal to triangle FPE.

So AP=EF

Question 10:

Question 1 1

Question 12:

(1) is stable and vertical in liquid. Continuous increase

(2) unchanged, unchanged, unchanged, more

(3) Stick and copper wire, winding an appropriate amount of copper wire at one end of the stick, and marking the scale on the stick.

Question 13:

Sink, because the spring scale provides a pulling force of 1.8 N, and the metal block is kept in the middle of the liquid. When cutting thin wires, the metal block will be subjected to unbalanced vertical force of 1.8N, so the metal block will sink.

God, I'm exhausted. . . . Sorry, the question is not difficult, typing and drawing are too difficult)