There are x members in the team.
5x=4x+ 15+9
5x-4x= 15+9
2.
A middle school organizes a spring outing for junior one students. It was originally planned to rent a number of 45-seat buses, but 15 people had no seats. If you rent the same number of 60-seat buses and have one more, the rest will be just full. We want to ask
(1) What is the number of students in Grade One? How many 45-seat buses were originally planned to be rented?
Solution: Rent 45-seat bus X and 60-seat bus (x- 1).
45x+ 15=60(x- 1)
Solution: x=5 45x+ 15=240 (person)
The number of students in Grade One is 240.
It is planned to rent five 45-seat buses.
3. Input a batch of accounting statements into the computer. It takes 20 hours for Party A to do it alone, and it takes 12h for Party B to do it alone. Now Party A works alone for 4 hours, and the rest is done by both parties. How long will Party A and Party B cooperate?
Solutions; Set to XH
1/5+ 1/20X+ 1/ 12X = 1
8/60X=4/5
X=6
The cooperation time of A and B is 6H.
4. The sum of the numbers A, B and C is 53, so the ratio of A to B is 4: 3, C is 2 less than B, B is () and C is ().
Let a be 4X. Then b is 3X. C is 3X-2.
4X+3X+3X-2=53
10X=53+2
10X=55
X=5.5
3X= 16.5
3X-2= 16.5-2= 14.5
B is 16.5 and c is 14.5.
The length of thick candle is the same as that of thin candle. Thick candles can burn for 5 hours, and thin candles can burn for 4 hours. After the power failure, two candles are lit at the same time, and they are extinguished at the same time after the call. It turns out that the length of a thick candle is four times that of a thin candle. How long will it take for the power outage?
Set the power outage for x hours. The thick candle burns 1/5 per hour, and the thin candle burns 1/4 per hour.
1- 1/5X = 4( 1- 1/4)
1- 1/5X=4-X
- 1/5+X=4- 1
4/5X=3
X= 15/4
6. For a three-digit number, the number of the hundredth digit is greater than the number of the tenth digit 1, and the number of the tenth digit is three times smaller than 2. If the order of three digits is reversed, the sum of the obtained three digits and the original three digits is 1 17 1, so find these three digits.
Let ten digits be x.
Then100× (x+1)+10x+3x-2+100 * (x+1)+/kloc-0+.
simplify
424x= 1272
So: x=3
This three-digit number is 437.
7. Three classes in Grade One and Grade Three donate books to Hope Primary School. A class library 152 volumes. The number of books donated by Class Two is the average of three classes. The number of books donated by Class Three accounts for 40% of the total number of books donated by Class Three. How many books did Class Three donate?
Solution: Set up 2 classes to donate X copies.
3x= 152+x+3xX40%
3x= 152+x+6/5x
3x-x-6/5x= 152
4/5x= 152
X = 190...(2) Class
190X3=570 (Ben)
8. The distance between A and B is 365,438+0 km. An hour later, A rode a bicycle from A to B, and B rode a motorcycle from A to B. It was known that A was driving at a speed of 12km, and B was driving at a speed of 28 km. How many hours did B catch up with A after departure?
Let b catch up with equations a and b x hours after departure.
12 (x+ 1) = 28 x = 0.75 hours, or 45 minutes.
1. In the history of sports, the speed of a person's heartbeat is usually related to his age. If A represents his age and B represents the maximum number of heartbeats per minute that he can bear during normal exercise, then B=0.8(220-A). Is it dangerous for a 45-year-old to have 22 heartbeats in ten seconds when exercising?
Solution: Substitute A=45 into B=0.8(220-A).
B=0.8(220-45)
B= 140
60/10 = 6,6 * 22 =132 (times)
132< 140
A: There is no danger.