Questions about math exams! Help me

The point is that your comprehension and analytical skills are not enough, you can read the question several times to figure out the principle. Then your math skills will improve. When you have time, you can copy the smarter ones and tell you about them with your better classmates, and ask the teacher if you don't understand.

Slowly, your math scores go up. I will do it during the exam and the accuracy rate should be 100% The more difficult ones will be solved slowly The most important thing is not to be nervous!

Practice more at home, listen carefully in class, and most importantly; Believe in your efforts and remember not to leave the questions blank when you take the exam, otherwise the score of the whole question will be gone, otherwise you will still get some points.

Oh I'm a sophomore in junior high school some time ago because factoring will not be troubled, but I have always believed that I can do it, now, because of more advice from classmates, how hard I work, those factorization has been difficult for me to talk, landlord, to cheer up, since you think you study well, then you have to have more confidence! Come on!

I'm a freshman in junior high school, and I've had a similar problem, although I've participated in the Olympiad and won the first prize, sometimes there are people who can't, and it's normal for everyone to fail the exam.

Do what you can do and have an accuracy rate of 100% The more difficult ones in the back are slowly solved The most important thing is not to be nervous!

I'm also taking the high school entrance examination this year, so it's good to relax.

The cost of the goods is 18 yuan for Zhaochong, 79 yuan for A, and 100 yuan for the difference in hand, because it is fake, he wants to take another 100 yuan and falsely guess to B, a total of 100 + 18 + 79 = 197 yuan.

The answer was a little wrong in typing just now, and now it's corrected.,Please see**.。

-2 first eliminate the third column, then eliminate the last column, and finally the second-order determinant is direct, pay attention to the sub-symbol when eliminating.

This is a polar notation.

The center of the circle of 2acos(0-) is (a, 0) and the radius is a = cos + root number 3sin

2 (1 2cos + root number 3 2sin) = 2 (sin30cos + cos30sin) = 2sin (+30).

2cos(60-θ)

So the center of the circle is (1,60 degrees) and the radius is 1

First, =cos +(3)sin is converted into a Cartesian coordinate equation, = cos +(3) sin ,x +y =x+( 3)y,x-1 2) +y- 3 2) =1

The center coordinate of the circle is (1 2, 3 2), the radius is 1, and then it is transformed into the polar coordinate, and the center coordinate of the circle is (1, 3), and the radius is 1

Original formula = 2 (1 2cos + half of the root number 3sin) = 2 (sin30 degrees cos + cos30 degrees sin) = 2sin (+30 degrees).

This kind of problem is to merge two trigonometric functions into a single trigonometric function, and it's not about finding the coordinates of the center of a circle, but it's a formula that you will learn in compulsory courses 4 and 5 in the first year of high school.

The center of the circle of 2acos(0-) is (a, 0) and the radius is a = cos + root number 3sin

2 (1 2cos + root number 3 2sin) = 2 (sin30cos + cos30sin) = 2sin (+30).

2cos(60-θ)

So the center of the circle is (1,60 degrees) and the radius is 1

=cos +(3)sin can be converted to =cos +(3) sin

²=x²+y²,ρcosθ=x,ρsinθ=y∴x²+y²=x+(√3)y

The shift is simplified to (x-1 2) +y- 3 2) =1 The center coordinates are (1 2, 3 2) and the radius is 1, and then the polar coordinates are obtained to obtain the center coordinates of the circle (1, 3) and the radius is 1

Top dog! I didn't understand the title!

You don't seem to have all the questions, do you?

This may seem like a simple idea.

It's time to take the test, and I've done a lot of these types of questions.

1. As can be seen from the title, the eligible pull can only be used as the base of the width, and the area of the parallelogram with a height of 12 is 10*12=120

The reason is that the height of the parallelogram must be perpendicular to the bottom, that is, the side and the height of the pull form a right-angled triangle, and the hypotenuse of the right-angled triangle must be greater than the right-angled side, so there are only 15 greater than 12, so it can only pull 15 as the hypotenuse to move. And the width of 10 as the base.

2. Suppose the third child pays $10,000 yuan.

That is, the second child is out (50+x) 20,000 yuan.

The third child has x million yuan and x = (boss + second) 3 = 3 to solve x = 300,000 yuan cavity hail wisdom.

That is, the second child paid 400,000 yuan.

Therefore, the villa is a total of 1.2 million yuan.

3. Suppose there are x people in workshop A and y people in workshop B.

Therefore x:y=3:5

x-150):(y+150)=3:7

Solution: x=750, y=1250

Fourth, assume that the question X is correct.

8x-(15-x)*4=72 gives x=11

Xibu: Set the second out of x million yuan, the third out of y million yuan.

50+y=2x

50+x=3y

x=40 y=30

The second is 400,000 yuan, the third is 300,000 yuan, and the price of this villa is 1.2 million yuan.

Set 3x people for A and 5x people for B.

7*(3x-150)=3*(5x+150), x=250

A 750 B 1250

Set up Pi to talk about Pi to do the right X question.

8x-4*(15-x)=72

The solution is x=11

He got 11 questions right.

See the posture chain nucleus call to block the map digging.

Oh, I can't do math.

Will be the last question. There are (n+1) (n+2) eggs in the nth layer.

There are 8*9=72 eggs, a total of 238 eggs.