Math awesome help!! Math is good to help!!

Why are today's children so lazy?

pieces (point: assuming the original plan to produce x parts, then there is, and the solution is x = 780).

2. Hours! If the work is 1 unit, the speed of A is 1 6, and B is 1 4, then it is (1-2*1 6) (1 6 + 1 4) 3, and the price is X

x[10+40]=[15*10+

x=4, set x fold.

500x/10-400=

The yuan is 1 3 * 1 3 = 1 94 (1 9) = 4 * 9 = 36 yuan of the money that Xiaohong asked for from her mother.

Xiaohong asked her mother for 36 yuan.

2. Earned 7200 * 20% = 1440 yuan.

Loss of 7200 80%-7200 = 1800 yuan 1800 1440

So I lost money selling these two computers.

It's very simple, the first question, she still has 4 yuan left in the end, which is the rest of the drink, that is, the third, and then you can calculate the remaining 12 yuan after buying a gift.

And this is the remaining third of the gift, so it is calculated that a total of 36 yuan is required.

The second question is that a computer earns 20% of 7200, that is, 1440 A computer is sold for 7200 and loses 20%, that is, it only sells 80% of the original price, the original price is 9000, and it loses 1800

As a result, the merchant lost a total of 360

1. After Xiaohong bought the gift, she left: 4 (1-2 3), so she asked her mother: 4 (1-2 3) (1-2 3) = 36 yuan.

2. The original price of the money-making computer is 7200 (1+

The original price of the losing computer was 7200 (.).

Therefore, a computer that loses money is more expensive than a computer that makes money, and if it is the same 20%, it will end up being a loss.

(1) Set Xiaohong to X yuan.

x—（2x/3+（x—2x/3）2/3）=4x=36

2) Let one of them have a purchase price of x yuan, and the other has a purchase price of y yuan x+

x=6000

y—y=9000

Total purchase price: 6000 + 9000 = 15000

Total selling price: 2 7200 = 14400

Answer: The loss is 600 yuan.

4 (1-2 3-1 3x2 3)=4 1 9=36 yuan7200 (1+20%)=6000 yuan, make 7200-6000=1200 yuan.

7200 (1-20%) = 9000 yuan, loss 9000-7200 = 1800 yuan.

So the loss: 1800-1200 = 600 yuan.

Set up x kilometers of buses, and the city charges are the same.

x=6A: Take 6 kilometers by car, the city fee is the same.

Set x kilometers, the charge of AB city is the same.

x = 6 for 6 km, the city toll is the same.

10+（x-3）*

x=6 The fare is the same for a 6 km ride.

If you take a bus x km, the charges in cities A and B are the same.

10+（x-3）*x=6

The area of the plane figure enclosed by x=0 or x=44y=x 2 and y2 =4x is (0,4)( 4x-x 4) dx

4/3·x^(3/2)-1/12·x³|(0,4)=4/3·4^(3/2)-1/12·4³

Double Integrals Just look at the high math textbook, there are a lot of similar questions.

m=0 is obviously vertical.

y=-mxy=-1/m *x+2/m

The product of the oblique pin rate is -m*-1 m=1

So you can only swim m=0 perpendicular to each other.

Parallel m=0 holds.

1-3m):m=1:2m

2m(1-3m)-m=0

m(2-6m-1)=0

m(1-6m)=0

m = 0 or m = 1 6

AD is the angular bisector of the bac, so the first blank is the DAC

Be is the angular bisector of abc and the second blank is abc

cf is the angular bisector of acb, so the third blank can be filled with acf or bcf

Let these four numbers be x1, x2, x3, and x4 respectively, then we have:

x1+x3=2*x2...1)x3^2=x2*x4...2)x1+x4=16...

3)x2+x3=12...4) The joint solution of the equation obtains: these four numbers are ; Or.

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Diagram cavity Yan Hongwu book jujube Jane.

The words are ugly, make do with it.