It is known that: P = a square + 3AB + b square, q = a square-3ab + b square, and P - [q-2p - (- P-Q)] + r = a square + 2Ab + b square

It is known that: P = a square + 3AB + b square, q = a square-3ab + b square, and P - [q-2p - (- P-Q)] + r = a square + 2Ab + b square

Original left
=P-(Q-2P+P+Q)+R
=P-Q+2P-P-Q+R
=2P-2Q+R
That is 2p-2q + r = a square + 2Ab + b square
R = 2q-2p + a square + 2Ab + b square
Let P = a square + 3AB + b square, q = a square - 3AB + b square
Substitute r = a square - 10ab + b square

P (square a + square B) - Q (square a + square B)=

p(a²+b²)-q(a²+b²)
=(a²+b²)(p-q)

At the same time, the two trains leave 1082km apart and meet at 3.6 o'clock. At this time, car a travels 18km more than car B. how much does car B travel per hour
Kilometers?
Write the equation. 1082km is 1080km

If vehicle B travels x kilometers per hour, then vehicle a travels x + 18 / 3.6 = x + 5 kilometers per hour,
From (x + X + 5) x3.6 = 1082,
The result is x = 147.8,
A: car B travels 147.8 kilometers per hour

If the equation cos α ^ 2-sin α + α = 0

The equation cos α ^ 2-sin α + α = 0 is 0

How many hours does it take for a car to complete the whole journey

A car can travel 60 kilometers per hour from place a to place B, which can be reached in 4 hours. In fact, it can travel 100 kilometers in 2 hours. According to this calculation, how many hours does it take to complete the whole journey?
Positive ratio:
It takes x hours to complete the whole process
60×4/x=100/2
240/x=50
x=4.8
Inverse proportion:
It takes x hours to complete the whole process
100/2*x=60×4
50x=240
x=4.8

The second power of 16A is the second power of B, and the fifth power of 20a is the fourth power of B

Solution
16a²b²=4a²b²×4
20a^5b^4=4a²b²×5a³b²
About 4A and 178; B and 178;

Car a and car B respectively travel from a and B. car a travels 55 kilometers per hour and car B 60 kilometers per hour. When they meet, car a travels 20 kilometers more than car B
Find the distance between a and B
Answer tonight!

Encounter time = 20 ÷ (60-55) = 4 hours
Distance between the two places = (60 + 55) × 4 = 460km

The square of a plus the square of B equals 6, a times b equals 7, and a minus B equals 1

（a-b）²=a²+b²-2ab
=6-14= -8＜0
So there is no solution

(1) A and B leave from both places at the same time. They meet in 5 hours. When they meet, car a just makes 30% of the whole journey. How many hours does it take car B to complete the whole journey?
(2) Uncle Li typed a manuscript and finished 25% of the total on the first day. If he typed another 15 pages, he would have finished half of the manuscript. How many pages are there in total?

(1) A and B leave from both places at the same time. They meet in 5 hours. When they meet, car a just makes 30% of the whole journey. How many hours does it take car B to complete the whole journey?
5÷（1-30%）
=5÷0.7
=50 / 7 hours
(2) Uncle Li typed a manuscript and finished 25% of the total on the first day. If he typed another 15 pages, he would have finished half of the manuscript. How many pages are there in total?
15÷（1/2-25%）
=15÷0.25
=60 pages

For any real number m, the equation (m-1) x - (M + 1) y + m + 7 = 0 holds and the values of X and y are obtained
Last time I asked, I answered
(m-1)x-(m+1)y+m+7=0
mx－x－my－y+m+7=0
m(x－y＋1)－x－y+7=0
If we want to be established,
It must be X-Y + 1 = 0, X-Y = - 1
－x－y＋7=0 x＋y=7
Solving equations
x－y=﹣1
x＋y=7
We get x = 3, y = 4
But why do we want to be constant? It must be X-Y + 1 = 0
But can't m (X-Y + 1) and - X-Y + 7 be opposite numbers?

You think, M is a variable. If M takes a value such as a, the equation holds. M (X-Y + 1) and - X-Y + 7 are opposite numbers
Then, when m takes another number, such as a + 1, if (X-Y + 1) is not 0, then the value of M (X-Y + 1) will change, and m (X-Y + 1) and - X-Y + 7 are not opposite numbers, and the equation does not always hold