Answer a math problem in detail! Please help solve a math problem!

Solution: 1) 0 < x < = 50

After mobilizing x farmers to engage in vegetable processing, the total annual income of farmers engaged in vegetable planting should be (100-x)*3*(1+2x%), and it should not be lower than the total annual income of farmers engaged in vegetable planting before mobilization, that is, (100-x)*3*(1+2x%) = 300

0 < = x < = 50Since x>0, 0 < x < = 50

2) The maximum value of the real number a is 5

The total annual income of the farmers engaged in vegetable processing in 100 households is 3(a-3x 50)x, and it is required to be 3(a-3x 50)x < = (100-x)*3*(1+2x%)

Simplify, a<=1+100 x+x 25and the inequality holds for any x that satisfies the range of 0 < x < = 50. When x=50, 1+100 x+x 25 is the minimum.

Therefore, the maximum value of a that satisfies the condition is 1+100 50+50 25=5

Since 20 divided by 3 = 6 to 1, the 19th is a diamond, and then the 20th is the sun.

Calculation formula. 20 divide [because the keyboard does not have a division] 3 = 6....1

So the 19th is the diamond, and the 20th is the sun.

Sun + Sun + Prism) = 3

It can be seen that 18 is a prism.

then are all suns.

So 20 is the sun.

3x7=21 The 21st is the diamond and the 20th is the sun.

Different factors, not divided... For example, if A is 2 and B is 4, then the total cost is 14 yuan; In the way of small peaches, the final selling price is 15 yuan; There is still money to be made in this way; If it's all the same price, it's the same how you sell it, and if A is greater than B, you'll have to lose.

It took a total to buy fish:

3a+2b yuan.

Selling fish sold in total:

a+b 2)*5=5a+5b 2 yuan.

Lost money, note:

5a+5b/2)-(3a+2b)<0

2a-b/2<0

2a4a In other words, the average ** of the two fish bought later is 4 times greater than the average ** of the 3 fish bought at the beginning, so I lose money.

Little peach buys fish with money = 3a + 2b

Selling fish = 5(a+b) 2

Money earned = 5(a+b) 2-3a+2b=(b-a) 2 from the question (b-a) 2 0

So a b

It's been a long time since I've done a math problem.

The first is 1 49 and the second is 1 44

First question:

1-49, 49 numbers, the probability of occurrence of each number is the same, so it is 1 49 The second question:

You don't think of this problem as producing 6 numbers at a time, but randomly 6 times, each time producing 1 number, because the number produced cannot be the same, so every time 1 is generated, 1 must be subtracted, and 5 numbers will be subtracted on the 6th time, 49-5 = 44, and the probability of 15 in 44 numbers must be 1 44.

Thanks, a little jelly!! I don't know, right?!

The first one has a 1 in 49 probability of 15, because the odds of each number being chosen are the same, just like eating an apple or a pear if you choose one is 1 in 2...

The probability that the sixth of the six numbers produced by the second type is 15 is... Be... otz。。。

I'm @......Who's out of this question, I... I won't be able to do it... Tear...

I don't float away, I flee ...

I'm wondering why you would solve b=8....

Take your system of equations {b+a=11 1.

10b+a+45=10a+b 2.

By 1Rollout: b = 11-a

Substitute b = 11-a into 2

Then 10(11-a)+a+45=10a+11-a110-10a+a+45=9a+11

155-9a=9a+11

144=18a

a=8 substitute a=8 into 1, get b = 3

So the original number is 38

a=11-b

Substituting 10b+11-b+45=110-10b+b18b=54

b=3a=8

Are you doing the wrong thing? Let's take a look at this from me.

Let's do it again, I'll do it, a=8

Something wrong with you. Even if you solve this equation, it's 38.

Solution: (8 8) (12 8) = 2 3

Set the height to x cm

5-x）（12×8）=8×8x

480-96x=64x

160x=480

x=33cm=

Water is high in decimeters. Please, thank you!

It can be solved by a series of equations, let the unfinished is x meters, and the completed is x + 50 meters, please see ** for the detailed process.

1.There are 49 cases in total, so: the probability of being 15 = 1 492There are 49*48*47*46*45*44 cases.

The probability that the sixth number is 15 is: 48*47*46*45*44 Therefore, the probability that the sixth number is 15 is: (48*47*46*45*44) (49*48*47*46*45*44)=1 49

Both probabilities are the same

The probability of 1 is 1 49

2. From 1 to 49 numbers, 6 numbers (not the same) are randomly generated in turn, with a total of p6 49 methods, and the sixth number is 15, with a total of p5 48 methods, and the probability is (p5 48) (p6 49) = 1 49

Both probabilities are the same

As long as a number is generated, then the probability of that number is 1 49, which has nothing to do with the position.