The equation of 60% y + x = 400 is solved

The equation of 60% y + x = 400 is solved

The equation of 60% y + x = 400 is solved
One equation cannot be solved, two unknowns cannot be solved
It can only be converted to the equation form X = 400 - 60% y

1-7/4X=1/9
0.8+80%X=1

The equation of one circle and one degree
1-7/4x=1/9
1-1/9=7/4x
x=8/9*4/7=32/63
0.8+0.8x=1
0.8x=1-0.8=0.2
x=0.2/0.8=0.25

200 words of discovery composition in life

In our childhood, sometimes we had a wild imagination, which might become a great discovery or have solved an unsolved mystery of the world. Even if we were very naughty. When I was a child, I went to my uncle's house to play, because there was a small chicken raising place in my uncle's backyard, where the soil was rotten and damp, which was very suitable for Snake growth, so

How many kilowatts can a 500KVA transformer load?

The long-term allowable load is that the load rate of 380kW transformer in long-term operation should not exceed 85%. Generally, the power factor can reach 0.95 after 70% - 80% compensation
But the transformer allows short-term overload, and the overload capacity of oil transformer is stronger than that of dry transformer. In case of an accident, the dry transformer can operate for one hour under 120% load and the oil transformer can operate for two hours under 130% load

The area of a rectangle is the second power of 3a to the second power of 3B. If its side length is a + B, what is its perimeter

Width = 3 (A & # 178; - B & # 178;) / (a + b)
=3(a+b)(a-b)÷(a+b)
=3(a-b)
Perimeter
=2*(a+b+3a-3b)
=8a-4b

What are the common units of electric power and energy

The electric power is watt and kilowatt, and the electric energy is kilowatt hour

As shown in the picture, when Wang Hua walks from B under street lamp a to C at night, he measures the length of shadow CD to be 1 meter. When he goes on for 3 meters to reach e, he measures the length of shadow EF to be 2 meters. It is known that Wang Hua's height is 1.5 meters. (1) find the height of street lamp a; (2) when Wang Hua goes on for another 2 meters, what is his shadow length when he reaches f?

(1) Let BC = x m, ab = Y M, from the meaning of the question, CD = 1 m, CE = 3 m, EF = 2 m, height MC = ne = 1.5 m, ∵ abd ∽ MCD, ∵ Abf ∽ Nef, ∵ abbd = mccd, abbf = neef, YX + 1 = 1.51, YX + 3 + 2 = 1.52, the solution is x = 3Y = 6, and the height of street lamp a is 6 m. (2) as shown in the figure

The meaning of letters
Seek the main physical symbols and letters that can be used in high school and college physics and their meanings
It's better to add the physics constants commonly used in high schools and universities and their letter expressions

A ampere current symbol
V-volt voltage symbol
Ω ohm resistance symbol
W watt electrical power symbol
N Newton mechanics symbol
K-card heat symbol
I'll think about it later

There is a spring vibrator on a smooth horizontal plane, the stiffness coefficient of the spring is k, the mass of the vibrator is m, and the maximum velocity of vibration is v0. As shown in the figure, when the vibrator gently puts the mass m object on it at the moment of maximum displacement a, then (1) to keep the object and the vibrator vibrating together, what is the friction coefficient between them at least? (2) When they vibrate together, how fast do they pass through the equilibrium position? What is the amplitude?

(1) After placing the object, assuming that it vibrates together, the maximum acceleration can be: a = Kam + m, at this time, the friction force is the largest. Taking m as the research object, according to Newton's second law: F = ma = mkam + m and F = μ mg, we can get: μ = Ka (M + m) g, that is, to keep the object and vibrator vibrating together, the friction factor between them is at least Ka (M + m) g

In AC circuit, will a capacitor connected in parallel at both ends of the resistor change the voltage at both ends of the resistor

After the capacitor is charged, the current of the branch where the capacitor is located is zero. The voltage at both ends of the capacitor is equal to that of the two points in parallel. Therefore, in AC circuit, a capacitor connected in parallel at both ends of the resistor will not change the voltage at both ends of the resistor