There are 50 RMB with one yuan, two yuan and five yuan. The total face value is 116 yuan. There are two more RMB with one yuan than two yuan. How many RMB with three face values?

Let 1 yuan have X pieces, 2 yuan (X-2) pieces, 5 yuan (52-2x). According to the meaning of the question, we get x + 2 × (X-2) + 5 × (52-2x) = 116, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; X + 2X-4 + 260-10x = 116, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & n

There are 50 pieces of RMB 1 yuan, 2 yuan and 5 yuan, with a total face value of 116 yuan. It is known that there are two more pieces of RMB 1 yuan than that of RMB 2 yuan. How many pieces of each of the three kinds of RMB? The solution of the equation should be written step by step, otherwise you can't understand it

Let 1 yuan have X Yuan, then 2 yuan have (X-2) yuan, then 5 yuan have 50-x - (X-2) yuan. According to the title, the face value is 116 yuan, then x + 2 * (X-2) + 5 * (52-2x) = 116 yuan
x+2x-4+260-10x=116
7x=140
x=20
So there are 20 for $1, 18 for $2 and 12 for $5

Given constant a, B and positive variable x, y, satisfy a + B = 10, a / x + B / y = 1, the minimum value of X + y is 18, find the value of a, B
--------Dear friends, please pay attention---------
What I want to ask is: if we want to prove that a and B are normal numbers according to the basic formula of inequality?

X + y = (x + y) (A / x + B / y) because the latter is equal to 1 = a + B + ay / x + BX / y = 10 + ay / x + BX / yay / x + BX / y. if there is a minimum value, then a > 0, b > 0, X / Y > 0 (x, y are positive numbers, if a, B are less than 0, then ay / x + BX / y can not have a minimum value). In this case, ay / x + BX / Y > = 2 √ (ay / X * BX / y) = 2 √ AB, so x + Y > = 10 + 2 √ AB

A and B cars leave from ab at the same time. The speed of a car is 3 / 5 of that of B car. The two cars meet 24 kilometers away from the midpoint. How many kilometers is the distance between AB and ab?
I hope to write my thoughts,

24×2÷（5-3）×（5+3）
=24×8
=192 (km)

It is known that one of the univariate quadratic equations X & # 178; + (A & # 178; - 1) x + A-2 = 0 is larger than one, and the other is smaller than 1. The value range of real number a is obtained
Let m ∈ r solve the inequality about X: MX & # 178; - (M + 1) x + 1 < 0. Why do we discuss M = 1, M > 1, m < 1? Can we discuss other numbers? Or is 1 simple?

A:
1) X & # 178; + (A & # 178; - 1) x + A-2 = 0, one root is less than 1, one root is greater than 1
The parabola f (x) = x & # 178; + (A & # 178; - 1) x + A-2 has two zeros with its opening upward
f(1)

Passenger and freight cars travel from a and B at the same time. Passenger cars travel 63 km per hour and freight cars take 8 hours to complete the whole journey
Passenger and freight cars travel from a and B at the same time. Passenger cars travel 63km per hour, freight cars travel 8 hours, passenger cars travel 9 / 16, and trains travel 15 / 28. How many kilometers are there between a and B

Speed ratio: Truck = 9 / 16:15 / 28 = 9 * 28 / (16 * 15) = 3 * 7 / 5 * 4 = 21 / 20
Truck speed = 63 * 20 / 21 = 60 km / h
Therefore, the distance between a and B is 8 * 60 = 480km

What shape is the projection energy of a projective plane in a Euclidean three-dimensional coordinate system
Projective plane is a concept of topological geometry, which is a three-dimensional manifold that can be seen in four-dimensional space. The answers on the first three floors are too layman.

I don't know what the Euclidean 3D coordinates are!
I only know the shadow of a plane in a 3D view
It should be a right angle
It's supposed to be an equiaxial coordinate system

There are 152 people in class A and class B. There are 82 people in 5 / 8 of class A and 4 / 9 of class B. how many people are there in each class

If you are a primary school student, do this. Suppose the number of class A is x (152-x) * (4 / 9) + (5x) / 8 = 82, then x = 80. 152-80 = 72. Explain that 152-x is equal to the number of class B, and then multiply by 4 / 9

From the natural numbers of 1-100, add two different numbers each time to make the sum greater than 100?
Simplify the formula and write down the answer

1+100
2+100,2+99
3+100,3+99,3+98
4+100,4+99,4+98,4+97
……
50+51,50+52…… ,50+100
It can be concluded from the above figure that there are three aspects
1+2+3+…… 50 = (1 + 50) X50 / 2 = 1275 species

The car is driving on the expressway at the speed of 120km / h, and the car in front suddenly stops in the road due to the accident. The driver finds that there is danger ahead, and it takes 0.7s to react and immediately brake. This time is called reaction time. If the maximum acceleration generated by the car when braking is 10m / S ^ 2, the maximum acceleration is 10m / S ^ 2, The braking process of a car can be regarded as a straight line motion with uniform deceleration. Try to find out how far away the car is from the car in front before the rear end collision accident does not occur

1. The converted vehicle speed of 120km / h is about 33.33m/s
2. S = (33.33*0.7) + (33.33*33.33/10)/2 = 23.331 + 55.544 = 78.875 m
At least 78.875 meters

There are 50 RMB with one yuan, two yuan and five yuan. The total face value is 116 yuan. There are two more RMB with one yuan than two yuan. How many RMB with three face values?