How much is a kilogram of copper aluminum alloy

Look at the amount of copper and aluminum!

Congruent triangle problems
1. As shown in the figure, it is known that AB / / CD, O is the midpoint of BD, and the straight lines passing through o intersect CD, AB at e and f respectively,
The proof is: (1) OE = of
(2) If e and F are the midpoint of DC and ab respectively, then angle a = angle B
2. It is known that AB / / CD, ab = CD, BD and AC intersect at point O, EF passes through point O, AB intersects at point E, and CD intersects at point F

1 (1) ∵ab//cd
∴∠fbo=∠edo
∵ o is the midpoint of BD
∴bo=do
∵∠fob=∠eod
∴△fob≌△eod
∴oe=of
(2) The second question really can't find the angle a = angle B. give me a picture
2 ∵ab//cd
∴∠bao=∠dco ∠abo=∠cdo
∵ab=cd
∴△abo≌△cdo
∴oa=oc
∵∠aoe=∠cof
∴△aoe≌△cof
∴oe=of

How to write 2:40 in English

Two last four or two to three

The composition of reading experience

When I was a child, I grew up in the poetry of "weeding day in the afternoon, sweat dripping down the soil". Every time I picked up the book and looked at the lifeless square characters, I always yelled that it was meaningless. Reading is my biggest headache. Gradually growing up, I feel the lack of knowledge. Every time I write a composition, I don't know where to start

How to improve the fifth grade mathematics achievement?

The key to improve the academic performance is to listen carefully in class. No matter which subject you are in, you must ask the teacher or the students with excellent performance for questions you don't understand. Don't be ashamed to ask. Compared with other subjects, mathematics has a more prominent characteristic: it can't keep up step by step, it can't keep up step by step, and it will fall more and more. Therefore, in order to improve the academic performance, you must digest the knowledge of the day, Never be in debt

4X + 5 × 6 = 58 solve equation and check calculation

4x+5×6=58
4x+30=58
4x=28
x=7
4*7+5*6=28+30=58

-100-99-98-...-1+0+1+2+.+50
Decrease from - 100 to 0 and then increase to 50

-5050 + 1275 = 3775 thank you

Answer to the fifth question of exercise 7.5 in the seventh grade mathematics exercise book of Shandong Education Press
Uncle Wang saved 1000 yuan and 20000 yuan respectively in two ways. He took them out one year later and got interest of 457.2 yuan

Let 1000 yuan interest rate be x and 20000 yuan interest rate be (0.0297-x). 1000x + 20000 (0.0297-x) = 457.21000 x + 594-20000 x = 457.2-18000 x = 457.2-594-18000 x = - 136.818 000 x = 136.8x = 0.00760.0297-x = 0.0297-0.0076 = 0.02210.0076 = 0.76% 0.0221 = 2.21%

The original price of a commodity is 289 yuan. After two successive price reductions, the price is 256 yuan. Suppose the average percentage of each price reduction is x, then the value of X is______ ．

Suppose the average percentage of price reduction is X. according to the meaning of the question, we get 289 × (1-x) 2 = 256, and the solution is x = 117 or x = 1817 (rounding off), so the answer is 117

If the function f (x) is a monotone function over the domain D, and there exists an interval [a, b] &; D (where a < b), such that when x ∈ [a, b], the value range of F (x) is exactly [a, b], then the function f (x) is said to be a positive function over D, and the interval [a, b] is called an equi domain interval
(2) Try to explore whether there is a real number m, so that the function g (x) = x2 + m is a positive function on (- ∞, 0). If there is, ask for the value range of the real number m; if not, please explain the reason
(2) Because the function g (x) = x2 + m is a decreasing function on (- ∞, 0),
So when x ∈ [a, b], the,
g(a)=bg(b)=a
Namely
a2+m=bb2+m=a
By subtracting the two formulas, A2-B2 = B-A,
That is, B = - (a + 1),
Substituting A2 + M = B, A2 + A + m + 1 = 0,
From a < B < 0,
And B = - (a + 1)
The result is - 1 ＜ a ＜ - 1 / 2
So the equation A2 + A + m + 1 = 0 of a has a real solution in the interval (- 1, - 1 / 2),
Let H (a) = A2 + A + m + 1,
be
h(-1)＞0h(-12)＜0
The solution is m ∈ (- 1, - 3 / 4)
By subtracting the two formulas, A2-B2 = B-A,
That is, B = - (a + 1),
How to do this?

From A2-B2 = B-A
Factorization factor (a-b) (a + b) = B-A
Extracting the common factor A-B & nbsp; & nbsp;
We get: (a-b) (a + B-1) = 0
From a ≠ B & nbsp; & nbsp; a + B-1 = 0
That is, B = - (a + 1)

How much is a kilogram of copper aluminum alloy