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I used 9 yuan to buy a duck, 10 yuan to sell out, 11 yuan to buy back, 12 yuan to sell out. Excuse me, how much money did I make?
It should be, the first time you sell it, you make a dollar, but you buy it at a loss of 2 yuan, so you lose one piece. In the end, you sell 12 yuan, 3 yuan more than the cost price, and finally make 2 yuan. This is the logic of buying and selling stocks
A / (7.2 + a) = 0.02, what is a?
A=0.02*(7.2+A)=0.144+0.02A
0.98A=0.144
A=0.147
a=60+k ar=100+k A (R) '2 = 150 + K (a times the square of R) How to calculate a,
a=60+k （1）
ar=100+k （2）
A (R) '2 = 150 + K (a times the square of R) (3)
(2) (1), a (R-1) = 40 (4)
(3) (2), AR (R-1) = 50 (5)
(5) (4), r = 5 / 4
Substitute (4) to obtain a = 160
Jinquan street reconstruction project headquarters, to bid for a certain section of the project, received bids from two engineering teams a and B. from the bidding documents, it is learned that the number of days required for team a to complete the project alone is 2 times of the number of days required for team B to complete the project alone 3. If the first 10 days by team a, the rest of the project by a, B cooperation can be completed in 30 days (1) How many days does it take for teams a and B to complete the project separately? (2) It is known that the daily construction cost of team a is 8400 yuan, that of team B is 5600 yuan, and the construction cost of the project budget is 500000 yuan. In order to shorten the construction period and reduce the impact on residents, it is planned to arrange team a and team B to cooperate to complete the project. Is the construction cost of the project budget sufficient? If it is not enough, how much additional budget is needed? Please give your judgment and reasons
(1) It will take X days for team B to complete the project alone, while it will take 2 days for team a to complete the project alone
3x days
According to the meaning of the title: 10
Two
3x+30×（1
Two
3x+1
x）=1．
The solution is: x = 90
It is proved that x = 90 is the root of the original equation
∴2
3x=2
3×90=60．
A: team a and team B need 60 and 90 days to complete the project separately
(2) It will take y days for a and B teams to cooperate to complete the project
Y (1
60+1
90）=1．
The solution is y = 36
Construction cost: 36 × (0.84 + 0.56) = 50.4
∵50.4＞50
The construction cost of the project budget is not enough, and an additional budget of 4000 yuan is needed
In the rectangle ABCD, point E is the midpoint of AB and de ⊥ CE. If the circumference of the rectangle is 30cm, calculate the lengths of AB and AD
Let AB = x ad = y;
Because de ^ 2 + EC ^ 2 = DC ^ 2 and root sign (de ^ 2 + EC ^ 2) = DC, here we can list an equation, which is: 2Y ^ 2-1 / 2 (x ^ 2) = 0
And perimeter = 30, so x + y = 15
By solving the equation, x = 10, y = 5
That is: ab = 10, ad = 5
If the circumference of an isosceles triangle is 24, the waist length is y, and the bottom side length is x, then the analytic formula of the function of Y with respect to X is______ The value range of the independent variable x is__________ ? The sum of the two sides is greater than the third side=||
Because it's an isosceles triangle
So the waist length plus the base length equals the circumference of 24
That is, 2x + y = 24
Then the function analytic formula of Y with respect to X is y = - 2x + 24
And because
The sum of the two sides is greater than the third
X is the waist length of the triangle
So x > 0
Bottom edge length Y > 0
So - 2x + 24 > 0
That is X
To ask math questions, for people in junior high school, The question is this: There are two barrels of oil, a total of 44 kg. If one fifth of the oil is poured out from the first barrel and 10 kg of oil is poured into the second barrel, the weight of the two barrels is equal. How many kilograms of oil are filled in each barrel? You'd better write down how you got it I always feel that the problem is embarrassing, and that's the name of the bandit,
My department is a professional mathematics teacher, so I don't speak very well. I have a way. I have a way. First, calculate the weight of two barrels after pouring. Set the first bucket weight as kg x, then the second bucket is (44-x) kg. (1-1 / 5) x = (44-x) + 10 -------- use the last "two barrels
Ask math questions Two mineral fruits, 30 kg more in frame than in basket B, 18 kg sold in B basket, only 2 / 5 (2 / 5) of basket a, how many kg of original fruit in B basket? I'm not talented, OTZ
Let B basket have a kilogram,
Then a has a + 30,
a-18=2/5(a+30)
A = 50 is obtained
Therefore, there are B baskets of original fruits of 50 kg
Seven judges give a singer an average score of 9.6, with the highest score of 9.55, the lowest score of 9.7; if both the highest and lowest scores are removed, what is the average score? Don't just list
Through 9.6 * 7, the original total score was 67.2
After removing the highest and lowest points, the remaining points are given by the other five referees,
67.2-9.55-9.7 = 47.95
Because this is only the score of the remaining five referees, then 47.95 divided by 5 is the final score, the result is 9.59
I hope it can help you
Number a minus number B is equal to 36.63. If the decimal point of number a is moved to the left by two places, it is equal to number B. what are the two numbers of a and B?
Number B: 36.63 ^ (100-1)
=36.63÷99
=0.37；
A number: 0.37 × 100 = 37;
A: number a is 37, number B is 0.37
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