Two questions of binary once applied questions

Two questions of binary once applied questions

1) A factory bought 56 tons of a and B materials, which cost 9860 yuan. If a material is 190 yuan per ton and B material is 160 yuan per ton, how many tons of the two materials will be bought and how much will it cost to buy the two materials?
2) There are two kinds of bonds with annual interest rates of 10% and 12% respectively. The existing 400 yuan bonds will earn 45 yuan a year later. How many are the two kinds of bonds?

A man bought a chicken for 8 yuan, sold it for 9 yuan, bought it back for 10 yuan, and sold it for 11 yuan. Why did he lose 2 yuan

If you buy a chicken for 8 yuan and sell it for 9 yuan, you'll earn 1 yuan. But if you buy a chicken for 10 yuan, you'll get no profit for 1 yuan. If you buy a chicken for 10 yuan and sell it for 11 yuan, you'll earn 1 yuan in total

Diamond ABCD, m, n are the points on BC, CD, am = an = Mn = AB, find the degree of angle c?

Because am = an = Mn, ∠ amn = ∠ MNA = ∠ man = 60 degree
And because the quadrilateral ABCD is a diamond,
So, B = D, bad = C, ab = ad,
So AB = ad = am = an
So, ABM = BNA = and = NDA,
Let ∠ ABM be X,
Then 360-4x = 180-x-60
The solution is 80,
Therefore, bad = C = 180-80 = 100
I.e. 100 ° for ∠ C

Factorization 25X & # 178; - 16y & # 178; is factorization,

（5x+4y)(5x-4y)

The polar coordinate equation of a line is θ = π / 4. How can it be transformed into a linear equation

As shown in the figure, in the known △ ABC, it is known that ∠ B = 65 °, C = 45 °, ad is the height on the side of BC, AE is the bisector of ∠ BAC, and the degree of ∠ DAE is calculated
(1) Find the degree of ∠ DAE
(2) If ∠ B ＞ C, ad is the height on the edge of BC, AE bisects ∠ BAC, and the verification is: ∠ DAB = & # 189; (∠ B - ∠ C)

It is known that ∠ DAE = 25 ° and ∠ DAC = 45 ° so ∠ a = 70 ° AE is the angular bisector, so ∠ EAC = 35 ° so ∠ DAE = ∠ a - ∠ EAC - ∠ DAB = 10 °

Is 550mg equal to 5.5 * 10 ^ (- 4) kg
Is it equal to 1 * 10 ^ (- 2) M & # 179;

Yes, both are right

If we know that f (x) = 1 / 2x + 1 x is less than or equal to 0 and the square X of (x-1) is greater than 0, then the value range of X which makes f (x) greater than or equal to - 1 is

f(x)=x/2+1 (x0)
f(x)>=-1
x-1
x/2>-2
x>-4
-4-1
(x-1)²

If we know that one side of an isosceles triangle is 6, and an outer angle is 120 °, then its perimeter is?
There is no picture

If 6 + 6 + 6 = 18, an external angle of a triangle is 120 degrees, then 180-120 = 60 degrees, plus this is an isosceles triangle, then you can know that each angle is 60 degrees, that is, an equilateral triangle

Given that the sinusoidal voltage is 220 V at t = 0 and its initial phase is 45, what is its effective value?

According to u = um * sin (WT + φ) = um * sin (WT + 45)
When t = 0, u = 220 V,
So, 220 = um * sin45,
Um=220/sin45.
Voltage RMS = um * √ 2 / 2 = √ 2 / 2 * 220 / sin45 = 220 V