Xiaoying and several students went to the stationery store to buy exercise books. The stationery store stipulated that if the purchase reached a certain quantity, they could buy them at the wholesale price. So they gathered together 60 yuan to buy them at the wholesale price. In this way, the number of exercise books purchased was 30 more than that purchased at the retail price. If the wholesale price of each exercise book was 45 times of the retail price, what was the retail price of each exercise book How much is it?

Suppose the retail price of each exercise book is x yuan, then the wholesale price of each exercise book is 45x, according to the meaning of the question: 6045x − 60x = 30, the solution is x = 0.5

Stationery shop owners come in with a batch of notebooks and plan to increase the price by 20%. When they sell half and 20 copies, they can recover the cost and get half of the expected profit
How many notebooks are there in this batch?

Suppose there were x copies in total
If the purchase price of each book is regarded as unit 1, the selling price is 1 + 20% = 1.2
（X/2+20）×1.2=X×1+X×20%×1/2
0.6X+24=X+0.1X
0.5X=24
X=48
Have a good time

A supermarket used 50000 yuan to purchase a batch of "T-shirts" from other places. Due to good sales, the supermarket had 18 urgent allocation
Fractional equation
A supermarket used 50000 yuan to purchase a batch of "T-shirts" from other places. Due to good sales, the supermarket had 18 urgent allocation
16000 yuan more than the last purchase of "T-shirts", but the second purchase price is 12 yuan more than the first purchase price, so how many "T-shirts" did the supermarket make before and after two times

Let the first purchase price be x yuan per piece
According to the condition of the title: 3 * (50000 / x) = 186000 / (x + 12)
The solution is x = 50
A: 50000 / 50 = 1000 pieces for the first time
186000 / (50 + 12) = 3000 pieces for the second time
4000 pieces in total

How many square meters is one square foot?

One foot equals 10 feet, so one square foot equals 100 square feet
1 meter = 3 feet, so: 1 square meter = 9 square feet
So: one square foot = 100 △ 9 ≈ 11.11 (square meter)

Two trucks delivered seedlings to the town. The first one drove to the town at the speed of 30 km / h, and the second one drove to the town at the speed of 40 km / h from the same place. As a result, the two trucks arrived at the same time. Q: how far is it to the town?
It's OK to use arithmetic, it's OK to use equations, it's OK not to have fractions
No, wrong type,

It takes X minutes for the first bus to get to the town
30x=40(x-10)
x=40
Distance = time × speed = 30 × 40 = 1200 meters
A: it's 1200 meters to the town
Hope to help your study ~!

1. Y = cos (2x + 60 °) + SiN x squared
If a curve is translated by vector (- 2,0), then x in the curve becomes x + 2. Is it translated by vector or by translation rule

It's easy to simplify the formula of trigonometric function's sum of two angles and double angle!
cos(2x+60°)+(sin x)^2=cos60°cos2x-sin60°sin2x+(sin x)^2
=1/2[1-2(sinx)^2]-√3/2×sin2x+(sin x)^2
=1/2-√3sin2x/2

How many liters is one cubic meter

1000

Why is the mathematics of grade one so difficult? Is there any way to solve it?

Master some typical problem-solving skills and methods, remember some useful theorems
There is no other good way to strengthen the usual application and consolidation, just learn it

101 * 7 / 10-7 / 10 (simple calculation)

101 * 7 / 10-7 / 10
=7 / 10 × (101-1)
=7 / 10 × 100
=70

1,2,3,4,5,6,7,8, plus the operation symbol, make the result equal to 100

1x2+3x4+5x6+7x8=100

Stationery shop owners come in with a batch of notebooks and plan to increase the price by 20%. When they sell half and 20 copies, they can recover the cost and get half of the expected profit How many notebooks are there in this batch?