Ask the master to solve a few math problems correctly 11 45 ago

1. The alcohol concentration of A itself is 0, and adding 50% solution is equivalent to (50%+0) 2=25%.

The solution poured from A back to B is equivalent to (50%+25%) 2=

1.Answer:

Solution: Suppose there is one unit of water in cup A and two units of solution (one unit of water, one unit of alcohol) in cup B

After the first pour: A cup of alcohol concentration: (1 2) (1+1) = ,..Two. Second.

There are people, alas.

Question 1:

Question 2: It can be regarded as 10000*9999-9999+19999=9990000+10000=100000000

Kilometer. 2.Side area (1*m² area per minute square meter Three-fifths of an hour is 36 minutes, so three-fifths of an hour's area is.

3.Let the distance be in units of "1" and the speed of going up the hill is 1/30th. The velocity at which the lead hits the mountain is (1 30)*(1+.)

Then use the distance "1"Divide by the speed to get the answer and go down the hill in 23 minutes.

25 questions:

2（a-3）＝

2+a) 3, find the inequality.

a（x-5）/7＞x-a

The solution set about x.

Solution: 2(a-3) (2+a) 3

6a-18＝2+a

5a 20a 4, substituting a 4 into the inequality yields:

4（x-5）/7＞x-4

4x-20）/7＞x-4

4x-20＞7x-28

3x＜8x＜8/3

x＜2+2/3。26 questions:

10＝1km

10+4+6+10+|-3-5-8-3-6-4|59km yuan.

Taxis are 1km east of the departure point;

The taxi trip is 59km

The turnover is RMB.

Question 27: Let the original price be x:

90%〔x（1+15%）〕

x＝790%+90%×15%）x-x＝7

3/20）x-x＝7

27/200）x-x＝7

207/200）x-x＝7

1+7/200）x-x＝7

x+7/200x+x＝7

7/200x＝7

x＝7÷（7/200）

200 yuan. 28 questions:

Half an hour is 30 minutes, 1 3 hours is 20 minutes.

Let Xiaojie's velocity be x, and establish the equation:

4+x）×32/60

4+x）20/60，8/15（4+x）

1/2×4+（4+x）/3，32+8x＝30+20+5x

3x＝18x＝18/3＝6km

The speed of Xiaojie is 6kmh

Solution: Set the correct x question.

4x-1（25-x）=85

4x-25+x=85

5x=110

x=22 got it? I don't know how to look for me.

If Xiaoqin does the x question correctly, it will do the wrong (25-x) question.

4x-（25-x）=85

x =22

First, f(x+1) is found by the analytic expression of f(x), because the inverse function of f(x+1) is symmetrical with g(x) with respect to y=x, which means that g(x) is f(x+1) [definition of inverse function].

So just bring it in.

Let p=q=1 be substituted.

Get (a2) = 2 (a1) = -6

a1）=-3

a3）=（a2）+（a1）=-9

By analogy (an)=

a10）=-30

b should be changed to 6, otherwise the answer should be an algebraic --- with b

If you have any questions, please feel free to ask!

Proof: ABC and CDE are isosceles right triangles, acb= dce=90°

ac=bc，∠dc=ec，∠bce+∠ace=∠acd+∠ace=90°

bce=∠acd

In CDA and CEB.

ac=bc，∠acd=∠bce，dc=ec，∴△cda≌△ceb（sas）