4x-18 × 2 = 20 5 × 3.82-4x = 9.5 1 and 3 / 5 △ (x-0.45) = 16 / 5

4x-18 × 2 = 20 5 × 3.82-4x = 9.5 1 and 3 / 5 △ (x-0.45) = 16 / 5

4x-18 × 2 = 204x-36 = 204x = 20 + 364x = 56x = 145 × 3.82-4x = 9.519.1-4x = 9.54x = 19.1-9.54x = 9.6x = 2.41 and 3 / 5 ^ (x-0.45) = 16 / 5x-0.45 = 1 and 3 / 5 ^ 16 / 5x-0.45 = 8 / 5 × 5 / 16x-0.45 = 1 / 2x = 1 / 2 + 0.45X = 0.95

18%:3/20=x/6.5
All right, 30 minutes

0.18:0.15=x/6.5
x=6/5×6.5
x=7.8

1/6+1/12+1/20+1/30+1/42+…… +What is 1 / 132

1/6+1/12+1/20+1/30+1/42+…… +1/132=1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7..+1/11-1/12=1/2-1/12=5/12

There are 20 equations: 1 + 2 = 34 + 5 + 6 = 7 + 89 + 10 + 11 + 12 = 13 + 14 + 15 The sum of the left and right sides of the 20th equation is______ ．

According to the meaning of the question, the nth equation uses: 2n + 1 number; the 20th equation starts from 400, with 21 numbers on the left and 20 numbers on the right, namely: 400 + 401 + 402 + +420=421+422+… +439 + 440, the sum of the left and right sides is: (400 + 401 + 402 +) +440) × 41 △ 2 = 17220, then the 20th equation

[30/17+(Y-1.5)÷17/12]×51/8=12
What is y equal to?

Don't rush to work out every step. It will be much easier if you can reduce the score
[30/17+(Y-1.5)÷17/12]×51/8=12
30/17+(y-1.5)*12/17=12*8/51
(y-1.5)*12/17=12* 8/51-30/17
y-1.5=(12* 8/51 - 17/30 )* 17/12
y-1.5=1/6
y=5/3

Car a and car B travel from a and B. car a starts 15 minutes earlier than car B. car B's speed is 1.5 times that of car A. when they meet, car a walks 6km less than car B. It is known that car a's speed is 10km / h. The distance between a and B can be calculated

The total distance is x km
The speed difference between Party A and Party B is 5, walk less than 6km, 6 △ 5 = 1.2 (hours)
1.2×10+1.2×15=X
The solution is: x = 30
A: A and B are 30 kilometers apart

1. It takes 12 days for team a to complete a task alone, and 15 days for team B to complete it alone. How many days has team a been supporting for three days? After that, they can complete three-quarters of the task?
2. A project was completed in 14 days by Party A alone, 18 days by Party B alone, and 12 days by Party C alone. In the first seven days, Party A and Party B cooperated with each other and left for a period of time. In the last two days, Party B and Party C cooperated with each other and completed the task in nine days?

Question 1: if the workload is x and the time required for two teams to complete three-quarters of the task is t, then the working speed of team a is x / 12 and that of team B is x / 15, so
(x/12+x/15)t+x/12*3=3/4*x
The solution is: T = 10 / 3 days = 3.33 days
In the second question, suppose that the workload of the project is x, and Party B leaves for t days, so the work efficiency of Party A is x / 14, that of Party B is x / 18, and that of Party C is x / 12
(x/14+x/18)*（7-t)+x/14*t+(x/18+x/12)*2=x
The solution is t = 3 days

1. The purchase price of a schoolbag is 60 yuan. After 20% discount, the profit is 20 yuan
2. It is known that the sum of the original prices of a and B is 100 yuan. Due to market changes, the price of a is reduced by 10% and that of B is increased by 5%. After price adjustment, the unit prices of a and B are 2% higher than the sum of the original prices. What are the original unit prices of a and B?
3. If the price of a commodity is adjusted to 20% of the original price, the profit of the commodity is 10%, and the purchase price of the commodity is 1600 yuan. What is the original price of the commodity?
4. A person deposits several yuan in the bank as a three-year fixed deposit. Assuming that the annual interest rate is 5%, the actual interest after deducting income tax is 720 yuan (the tax rate of income tax on bank deposit is 20%, and the amount of income tax = income interest × 20%), how much is the principal deposited in the bank?

1. Suppose the original price of this schoolbag is x yuan
80%X—60=20
The solution is x = 100
A: the original price of this schoolbag is 100 yuan
2. Suppose that the original price of commodity a is X Yuan and that of commodity B is y yuan
X+Y=100
X（1—10%）+Y（1+5%）=100（1+2%）
The solution is x = 20
Y=80
A: the original unit price of commodity a is 20, and that of commodity B is 80
3. Suppose the original price of the goods is x yuan
0.8X-1600=1600×10%
The solution is x = 280
A: the original price is 280 yuan
The principal deposited in the bank is x yuan
5%×3X×（1—20%）=720
The solution is x = 6000
A: the principal deposited in the bank is 6000 yuan

In a certain kind of three color ice cream with a mass of 45g, the ratio of coffee, red and white ingredients is 1:2:6. What are the coffee, red and white ingredients in this kind of three color ice cream?
If the brown ingredient in this ice cream is XG, then the red and white ingredients are 2xg and 6xg respectively
X+2X+6X=45
To solve this equation, we have to
X=5
So 2x = 10, 6x = 30
I'm going to ask! Why 2x = 10? 6x = 30? How to calculate it?

Red and white ingredients are 2xg and 6G respectively
2X = 2 * 5 = 10g 6x = 6 * 5 = 30g

One piece of paper can make 16 bottles, 43 bottle bottoms and one bottle body with two bottle bottoms. It is a set of 150 pieces of paper
How many pieces of paper can be used to make the bottle body, and how many pieces of paper can be used to make the bottom of the bottle to make a matching bottle?
If you want to solve the equation, you'd better explain similar problems to me

Set X sheets of paper for bottle body
16X=43(150-X)/2
X=86
Answer: 86 pieces of paper for bottle body and 68 pieces of paper for bottle bottom