7. Li Ming has 50 pieces of RMB with denominations of 2 yuan and 5 yuan, with a total value of 208 yuan. How many pieces of RMB with denominations of 2 yuan and 5 yuan?

Simple: 14 for 2 yuan and 36 for 3 yuan
I learned it in junior high school. It's a two-way equation
Two yuan x, five yuan y
2x+5y=208
x+y=50

5 yuan, 10 yuan, 20 yuan, 100 yuan back scenery is where?

The fifth set of scenic spots on the back of RMB
100 yuan: the main scenery on the back of the ticket is "Great Hall of the people"
50 yuan: the main scene on the back is the "Potala Palace" pattern
20 yuan: the main scenery on the back of the ticket is "Guilin landscape" pattern
10 yuan: the main scene on the back is the pattern of "Three Gorges of the Yangtze River"
5 yuan: the scenery on the back is Mount Tai, in Tai'an, Shandong Province
1 yuan: the main scenery on the back is "Hangzhou West Lake"

When calculating the four mixed operations with brackets, we need to calculate them first And then ．

When calculating the four mixed operations with brackets, we need to calculate the one inside the brackets first, and then the one outside the brackets

There is a homogeneous rod with mass m and length L. it rotates around the end point of the rod with angular velocity W and perpendicular to the horizontal axis of the rod. The kinetic energy of the rod around the axis of rotation is? 1 / 6m * L ^ 2 * W ^ 2. Why is there 1 / 6
Why is 1 / 3 of 1 / 3M * L ^ 2 * W?

Taking the axis as the origin and establishing the X axis along the direction of the rod, the coordinate is x and the length of the rod is Δ x (Δ x)

It is known that the sum of the first n terms of the arithmetic sequence an is Sn, and A4 is 10, S4 is 22,

A4 is 10, S4 is 22, S4 = 4 (a1 + A4) / 2, A1 = 1
a4-a1=3d d=3
an=a1+(n-1)d=3n-2

If a trolley bus starts to slow down from 10m / s at a speed of 2.0m at the same speed, what is its displacement after 8 seconds
I know the answer is 25m. But why can we use v = at to find that it has stopped in 5 seconds?

Stop, that is, the final speed is 0,
0=10-2t
t=5s

Xiaoming's distance is one fourth more than Xiaoqiang's, but Xiaoqiang's walking time is one tenth more than Xiaoming's?

13705529806,
The distance ratio of Xiaoming to Xiaoqiang is as follows:
（1＋1/4）：1＝5：4
The time ratio of Xiaoming to Xiaoqiang was as follows
1：（1＋1/10）＝10：11
The speed ratio of Xiaoming to Xiaoqiang is as follows:
（5÷10）：（4÷11）＝11：8

Journey to the West and Xuanzang's Sutra (truth) which are fictional? What are the similarities

I know! Our history teacher said that
A: the same point: they are all for the purpose of seeking the Scriptures, and their destinations are all Tianzhu
Fiction: three disciples of Xuanzang, ghosts on the road

As shown in the figure, moving point a on the number axis moves 2 units of length to the left to reach point B, and then moves 5 units of length to the right to reach point C. if the number represented by point C is 1, then the number represented by point a is 1______ ．

Let the number corresponding to point a be X. then: X-2 + 5 = 1, the solution is: x = - 2. So the number represented by point a is - 2. So the answer is: - 2

A suit is 320 yuan in total. The unit price of trousers is 60% of that of top. How much more is the unit price of top than that of pants?

320 (1 + 60%), = 320 △ 1.6, = 200 (yuan); 200-200 × 60%, = 200-120, = 80 (yuan); answer: the unit price of coat is 80 yuan more than that of trousers

7. Li Ming has 50 pieces of RMB with denominations of 2 yuan and 5 yuan, with a total value of 208 yuan. How many pieces of RMB with denominations of 2 yuan and 5 yuan?