In the second year of junior high school, 50 points will be awarded for correct answers

1. Which of the following rational formulas are integers? Which are fractions?

3x ,1 ,x y), integer { 3x,1 ,(x y), fraction { 2, when the numerator is equal to 0, the value of the fraction is 0 ( false ) 3, the fraction must be meaningful ( wrong ).

4. When the denominator of x is 0, the fraction is meaningless;

When the denominator of x is not 0, the fraction makes sense;

When x, fraction x makes sense;

5. To make the formula meaningful, the value of x should be that the number after it is not 0.

6. When the x numerator is 0 and the denominator is not 0, the value of the fraction is 0.

7. The value of a that makes the fraction meaningful is (b).

a, a≠1 b, a≠ 1 c, a≠ 1 d, a are arbitrary real numbers.

8. When x = 3, the following fractions are meaningful ( ) a, b, c, d,

9. If the value of the fraction is negative, then x should satisfy (

a, x 5 b, x 5 c, x 0 d, x 010, when x takes what value, the following fractions are meaningless?

1) The denominator is 0 (2).

11. When x takes what value, fraction is meaningless?

Denominator = 012, when x takes what value, fraction makes sense?

The denominator is not 013, when x takes what value is the fractional value 0?

The numerator is 0 and the denominator is not 0

14. When x takes what value, the fractional value is positive?

The numerator and denominator symbols are the same.

15. If it represents an integer, what values can the integer a take?

Factor 16, observe the following column of regular numbers:

According to the law, it can be seen that the nth number should be (n is a positive integer).

It's not a problem, how can you do that? Do it yourself.

I'm lazier than you, it's too long to finish reading. The questions in junior high school are not interesting.

WWE Super Audience You did the second question wrong, and it's troublesome for me to do this question, and now I've made a picture for you to help understand (I found that I am very talented in drawing wohaha o( oha!) ）。Here's my answer to you.

Known: ab=3 3, bc=6, bpe=30°, ef is a broken line, trapezoidal fdce=fqpe;

Find: PE, QF; Area of PEFH.

Solution: 1) PE=EC, BPE=30°, B=90°, BC=6BE=PE2=EC 2=BC 3=2, BP=2 3 BPE=30°, EPQ=90°, AB=3 3AP= 3, APh=60°

a=90°=q

ph=2ap=2√3，ah=3,qf=hf/2=dfad=bc=6

qf=df=(bc-ah)/3=1

Trapezoidal FDCE = Trapezoidal FQPE

S quadrilateral PEFH = S trapezoidal FQPE-S QHF = S Trapezoidal FDCE=(FD+EC) DC 2=15 3 2,S QHF=QF QH 2= 3 2

s quadrilateral pefh = 7 3

1.Let be=x, then bp= 3x, pe=ce=2x.

Since bc=be+ce=6, then x=2, then.

be=2 Since the angle Fec = (180-60) 2 = 60, let df=y=qf, then hf= 3y

Since AD=AH+HF+DF=6 and AH=3, then QF=Y=1 so BE=2 and QF=1

2.The sought S = quadrilateral, ABCD-S, right-angled, trapezoidal, DFES-S triangle, APH-S triangle, PBE

As shown in the figure, AD is parallel to BC, AB=AD=DC, B=60°, E is a point on BC, F is a point on the CD extension line, and Be is equal to DF

1) Verification: AE AF

2) In Figure 1, if the point G is on CD and EAG is 60°, then BE+DG = EG? Why?

3) Use the experience and knowledge accumulated in the answers (1) and (2) to complete the following questions:

As shown in Figure 2, in the quadrilateral ABCD, b= c=60°, ab cd, ab=8, bc=16, , e is a point on bc, and ead=60°, be=6, find the length of de.

1) Verification: AE AF(2) In Figure 1, if the point g is on CD and EAG is 60°, then BE+DG=EG? Why?

3) Use the experience and knowledge accumulated in the answers (1) and (2) to complete the following questions:

As shown in Figure 2, in the quadrilateral ABCD, b= c=60°, ab cd, ab=8, bc=16, , e is a point on bc, and ead=60°, be=6, find the length of de.

Rotate 90 degrees clockwise with C as the center so that BC and AC coincide p fall to point D The simple PC=CD=2,BP=AD=1 and PCD=90 degrees PCD is isosceles rt is missing, CDP=45 degrees PD=2 times the root number2 and AP=3 According to the Pythagorean ADP is RT Shouxun PDA=90 degrees CDA= CP8=90+45=135 degrees, the main reason is that this idea is really hard to think!

135 degrees. I'm going to grind my limbs for reward. Rotate the triangle 90 degrees counterclockwise around point C. P to P then the triangle PBP is a right triangle and the triangle PCP is a mesobranched isosceles right triangle on OK

wa wa ..Someone robbed him. Slow typing. They all bullied me for being slow typing!

41:a

42:c43:b

44:c45: I'm sorry, I don't know (Is there a typo in B?) The invention of the battery was volts) 46:b

47:a48:c

49:c50:b

51: Uh-uh, what about your options?

52:c53:b

54:a55:c

56:b57:b

58:b59:c

60: carbon dioxide.

61:c62:b

63:a64:c

65:b66:c

67:b68:a

69: b70: Basically no carbon emissions.

While I can't guarantee 100% of the time it's right, I can't get it wrong, at most one or two.

The interval between the hanging windows is 2350 divided by 188 equals meters (here is the equidistant junction division of the ring.

Note that the divisor is 188, not 187).

No. 45 hanging window and No. 145 side by side.

There are 100 gaps between them.

There are 50 gaps left from the end point.

It's also just s=m.

The answer is 625 meters.

Math symbols are not easy to play.

I'll just use the Chinese character of trembling.

My answer.

By the way. Drawing is commonly used to solve such problems.

It's more intuitive. Writing can help you.

1.Answer: Because ad bc and ad=bc so.

The quadrilateral abcd is a parallelogram so ab=cd and the angle acd=angle bac because ae=cf so ce=af by the corners.

The inner side knows that the triangle describes the congruence of the triangle and the triangle abf, so de=cf and the angle cde=angle afb, so de bf