Mathematical master to solve (equation of one variable and one degree) A middle school requires students to build their own playground. It takes 7.5 hours to do it alone on the first day of junior high school; it takes 5 hours to complete it alone on the second day of junior high school? I've given you all my little fortune. I've written the title! I've got extra points in one hour!

Mathematical master to solve (equation of one variable and one degree) A middle school requires students to build their own playground. It takes 7.5 hours to do it alone on the first day of junior high school; it takes 5 hours to complete it alone on the second day of junior high school? I've given you all my little fortune. I've written the title! I've got extra points in one hour!

33333 hours

The solution of linear equation with one variable in Mathematics
A paper mill uses imported pulp to produce white paper. Each bundle of 1000 sheets is stacked together, which is a rectangle with a length of 320cm, a width of 240cm and a height of 20cm. If the pulp barrel is a cylinder with a bottom diameter of 180cm and a height of 180cm, and there is 15% pulp loss in the production process, how many sheets of white paper can be produced from each barrel? (π = 3.141)
First come first served

Is it possible? The paper has decimals

How to solve linear equation with one variable in Mathematics

General solution: 1. Remove the denominator: multiply the least common multiple of each denominator on both sides of the equation; 2. Remove the bracket: remove the small bracket first, then the middle bracket, and finally the curly bracket; (remember to change the sign if there is a minus sign outside the bracket); 3. Move the term: move the term containing the unknown number to one side of the equation, 4. Merge similar terms: change the equation to AX = B (a ≠ 0); 5. Change the coefficient to 1: divide the unknown coefficient a on both sides of the equation to get the solution x = B / A, Then the two equations are called the same solution equation. The same solution principle of the equation: 1. The equation obtained by adding or subtracting the same number or the same equation on both sides of the equation is the same solution equation with the original equation. 2. The equation obtained by multiplying or dividing the same number that is not zero on both sides of the equation is the same solution equation with the original equation

Mathematical solution of linear equation with one variable
The distance between station a and station B is 630km. An express train departs from station a at a speed of 120km / h, and a slow train departs from station B at a speed of 70km / h. If the express train starts driving for 30min, the two trains are facing each other. How long has the slow train been running? How long has the two trains met

The slow train ran for X hours and the two cars met
630=120*30/60+120x+70x
x=3

Three seventh of apples are bananas, two fifths of oranges are more than two thirds of bananas, and oranges are 40 kilograms
How many kilos does the apple have

Banana has: (40-2 / 5) / (2 / 3) = 59.4kg
Apple: 59.4 / (3 / 7) = 138.6 kg

π (Pie: 3.1415926...) Is minus 1 a monomial or a polynomial
Is π - 1 a monomial or a polynomial? Please tell me it's shrimp. 3Q

π - 1 is a monomial. Because π is a constant, 1 is also a constant

Conversion of physical density units,
1kg / M & # 179; = 10 to the power of - 3 g / M & # 179;
1m/s＝3.6km/h

There are 1800kg apples and pears in a fruit shop. One eighth of the apples are sold, and then 600kg pears are transported in. At this time, the quality of apples and pears is poor
There are 1800 kg apples and pears in a fruit shop. After selling one eighth of the apples, 600 kg pears are imported. At this time, the quality of apples and pears is equal. How many kg of apples did the fruit shop use
By the way, step by step, not equation --

One eighth of the apples were sold and another 600 kg of pears were brought in. At this time, the quality of apples and pears was equal
It turns out that pears are better than apples
1-1 / 8 = 7 / 8 less than 600 kg
1800 + 600 = 2400 (kg)
It's the original apple
1 + 7 / 8 = 15 / 8
There were apples
2400 △ 15 / 8 = 1280 (kg)

It is known that a minus B equals two. A minus C equals one-half. Then the formula. B minus the square enclosed by C. add three times the value of B-C plus nine fourths in brackets is. One is negative two thirds. Three twenty-two thirds. Three is zero and four is nine seventh. Would you like to choose one or two or three or four?

2

Let the real number a > 1 and the complex number Z satisfy (1 + AI) z = I + A, then the point corresponding to Z is in the complex plane

Let z = x + Yi, then
（1+ai﹚×（x+yi﹚=i+a
That is, (X-ay) + (AX + y) I = I + a
x-ay＝a
ax+y＝1
∴x＝2a／﹙1+a²﹚
y=﹙1-a²﹚／﹙1+a²﹚
∴x＞0 y＜0
The fourth quadrant