Inverse travel problem formula distance ÷ (large speed+small speed
The formula of the problem of traveling in the same direction is the distance ÷ (large speed-small speed)
The formula of navigation problem is the same as above.
Formula of train crossing bridge (train length+bridge length) ÷ speed
Engineering problem formula 1÷ speed sum
Profit and loss problem formula (surplus+deficit) ÷ twice the difference.
Interest rate problem formula Total profit/cost × 100%
Common formulas for mathematical application problems in primary and secondary schools
1, ask how many times rice is flour.
Rice =1/91/8 = 8/9 flour.
2. What is flour?
Flour =11900/(1+8/9) = 6300 kg.
3. Ask how much the rice is.
Rice = 1 1900-6300=5600 kg or
Rice =6300×8/9=5600 kg.
If you are a middle school student:
Let rice = x；; Flour =Y
1/8X= 1/9Y
X+Y= 1 1900
Just find x and y.
Solution: ask rice to be several times that of flour.
Rice =1/91/8 = 8/9 flour.
Find out how much flour it is.
Flour =11900/(1+8/9) = 6300 kg.
Finally, how much is the rice?
Rice = 1 1900-6300=5600 kg.
A: 5600 Jin of rice and 6300 Jin of flour were shipped back.
1 1900/ 17=700
Rice: 700*8=5600 (kg)
Flour: 70*9=6300 (kg)11900/(8/1+9/1) = 700 (kg).
Rice: 700/8 1=5600 (kg)
Flour: 700/9 1=6300 (kg)
Checking calculation: 5600+6300= 1 1900 (kg)
A: 5600 Jin of rice and 6300 Jin of flour were shipped back.
If you are a primary school student like me, and this application problem is your homework, you just need to copy down my algorithm (except the contents of calculation and the words rice, flour, etc. My algorithm is very good! ) One eighth of rice is equivalent to one ninth of flour, which means that the weight ratio of rice to flour is 8: 9, which means that rice accounts for 8/(8+9) of the total weight.
therefore
Weight of rice:11900× 8/(8+9) = 5600 (kg)
Flour weight:11900× 9/(8+9) = 6300 (kg)
Suppose there are x kilograms of rice, then there are 1 1900-X kilograms of flour.
According to the meaning of the question, we can get the equation X/8=( 1 1900-X)/9.
9X=8* 1 1900-8X
9X+8X=8* 1 1900
17X=8* 1 1900
X=5600 (kg)
Flour = 1 1900-5600 = 6300 (kg)
Brother, I am a middle school student. I will teach you how to solve this problem in middle school: binary linear equation.
Solution: let rice weigh x kilograms and flour weigh y kilograms.
X+Y= 1 1900 ①
X/8=Y/9 ②
①X= 1 1900-Y
Substitute ① into ② to get:
( 1 1900-Y)/8=Y/9
The answer is Y=6300.
Return the Y=6300 generation to ①, and get:
X+6300= 1 1900
X=5600
A: 5600 Jin of rice and 6300 Jin of flour were shipped back.
Copy according to the exercise book, and the teacher will definitely encourage you! Rice =1/91/8 = 8/9 flour.
Flour =11900/(1+8/9) = 6300 (kg)
Rice = 1 1900-6300=5600 (kg) Because rice is 1/8 and flour is 1/9, and rice accounts for 8/9 of flour,
(1+8/9) = sum of rice and flour 1 1900.
The weight of flour is:
1 1900÷( 1+8/9)
= 1 1900÷ 17/9
= 6300 kg
The weight of rice is: 6300×8/9=5600 (kg).
A: The weight of returned rice is 5,600kg, and the weight of returned flour is 6,300kg.