Fractional equation: to produce a certain kind of machine parts. It is planned to complete in 30 days. If 5 more parts are produced every day, then 10 more parts will be produced in 20 days. How many parts are originally planned to produce every day?

Fractional equation: to produce a certain kind of machine parts. It is planned to complete in 30 days. If 5 more parts are produced every day, then 10 more parts will be produced in 20 days. How many parts are originally planned to produce every day?

The original plan is to produce X parts per day
30X=20（X+5)+10
30X=20X+100+10
10X=110
X=11
1000% correct
Checking calculation: 30x11 = 330
20（11+5）+10
=220+100+10
=330

Processing a batch of parts, the original plan to process 30 per day, the plan to complete 1 / 3 of the improved technology, work efficiency increased by 10%, the results ahead of four days to complete the task!
How many parts are there in total!
Now, if you think the answer of this elder brother is correct, please tell me directly. If there are other solutions, please give me the process,

30 × (1 + 10%) = 33
30 × 4 ÷ (33-30) = 40 (days)
(40 + 4) / (1-1 / 3) = 66 (days)
30 × 66 = 1980
There are 1980 parts in this batch

What are the same words? What are the same scenery? What are the differences?
Note: one is tianjingsha · autumn, the other is tianjingsha · Qiusi

Lonely village sunset sunset sunset light smoke old trees jackdaw scenery: at dusk, crows are different: small bridge, flowing water, family
Withered vine, old tree, faint crow, small bridge, flowing water, family

On a plan with a scale of 1:500, the length of a rectangular classroom is 3cm and the width is 2cm. Write the ratio of the area on the plan to the actual area

The area on the picture is 3x2 = 6 square centimeters
Actual area (3x500) x (2x500) = 1500x1000 = 1500000 square centimeters
Area ratio 6 ∶ 1500000 = 1 ∶ 250000

The story about mathematicians should be short

Zu Chongzhi (429-500 A.D.) was born in Laiyuan County, Hebei Province during the northern and Southern Dynasties. He read many books on astronomy and mathematics since he was a child. He was diligent and practiced hard, and finally became an outstanding mathematician and astronomer in ancient China

Using the method of folding, a right triangle (∠ B = 90 degrees, ∠ C = 30 degrees) and an equilateral triangle are divided into three triangles of the same shape and size
Fold no more than three times

Right triangle - fold the 60 degree angle in half, then turn the 30 degree angle up
Equilateral triangle - take the midpoint of three sides and fold along the midpoint

Does the elevator move up and down

Yes, translation is parallel movement, no mechanical rotation, not just horizontal movement

Given the modulus 3 of vector a, the modulus 4 of vector B, and the angle between vector a and vector B is 60 degrees, then the projection of 2a-3b on B is

（2a-3b）b=2ab-3b*b=2*3*4*cos60-3*4*4=-36
The module of 2a-3b is √ (4 * 3 * 4-12 * 3 * 4 * 0.5 + 9 * 4 * 4) = √ 108
The cosine of the angle between 2a-3b and B is - 36 / (√ 108 * 4)
The projection of 2a-3b on B is the cosine of the angle between the module * of 2a-3b = √ 108 * (- 36 / (√ 108 * 4)) = - 9

As shown in the figure, the known points m and N are on the sides BC and Ca of equilateral △ ABC (equilateral triangle satisfies that all three sides are equal, and all three inner angles are equal to 60 °), am and BN intersect at point Q, and ∠ aqn = 60 °. Verification: am = BN

It is proved that: ∵ ABC is an equilateral triangle, ∵ AB = BC, ∠ ABC = ∠ C = 60 °, ∵ CBN + ∠ ABN = 60 °, ∵ aqn = ∠ BAM + ∠ ABN = 60 ° and ≌ BAM = ∠ CBN. In △ ABM and △ BCN, ≌ ABC = ∠ cab = BC ∠ BAM = ∠ CBN, ≌ ABM ≌ BCN (ASA) and ≌ am = BN

What's the answer to question 11 of the review question in Chapter 1?
It's problem 11 of exercise 1-3

（1）：
111 degrees = 0.601
Sin378 degree 21 '= 0.315
Cos642.5 degree = 0.216
（2）：
Sin (- 879 degrees) = -0.358
Tan (- 33 Pai / 8) = -0.414,
Cos (- 13 pies / 10) = -0.588
（3）：
sin3=0.141
cos （sin2）=0.614
(the equal sign means approximately equal to)