Elementary 1 Application problems of unary equations

Solution: Suppose: the original profit margin is x%, and the original purchase price is a

a（1+x%）=a（

x=17A: The original profit margin for distributing this product was 17%.

1. Let the ten digits be x, then the single digit is x+5 10(x+5)+x-(10x+x+5)=45 The formula is constant, so x can be 1, 2, 3, 4, and the two-digit number is 16, 27, 38, 49

2. Set the list price to x x=500, so the original price is +(x-1)*6000*

6000x*

6000 + (x-1) * 6000* = 6000 x * x = 5 So the charge is the same when selling 5 units.

6000+(x-1)*6000* <6000x* x>5 When the number of units sold is greater than 5, A is discounted.

When the number of units sold is less than 5, B is discounted.

Assuming that the time it takes to ride a bicycle from A to B at a speed of 12 km h is x hours, then the time taken to get from B to C is 55 60-x hours, and the speed from A to B is 12 km h, and the speed from B to A is 4 km h, then the time it takes is 12 4 = 3 times that of A to B, i.e. the time from B to A is 3x

then the time from place C to place B.

The column equation is: 12x+9*(55 60-x)=8*(

33/4-9x=12-24x

15x=12-33/4

15x=15/4

x=1 4, then the distance between A and C is 12*1 4+9*(55 60-1 4)=9km

1.Solution: It will take x hours for my brother to catch up with them.

2（1+x）=6x

2+2x=6x

x = points) 30 points 45 points. A: Yes.

3.(1) Solution: Let the speed of the aircraft be x per hour when there is no wind.

17/6（x+24）=3（x-24）

17/6x+68=3x-72

1/6x=-140

x=8402) 3*(840-24)=2448 (km)4Solution: It is set to be transferred to X people in the first place.

31+x=【21+（23-x）】*2

31+x=88-2x

3x=57x=19

5.Solution: Ask x workers to produce lenses.

200x=（60-x）50*2

200x=6000-100x

300x=6000

x=2060-20=40 (person).

A: There are 20 people who produce lenses and 40 people who produce frames.

In fact, some problems can be simpler with arithmetic, but now learn Fang Sun Jiancheng. Helpless. If you want to do the itinerary problem, you can try to draw the itinerary map.

Solution: 1. Assuming that it is more than 100, the ticket price per person is 9 yuan, 1080 9 = 120, known by the title, there are no less than 20 people in the seventh grade, and no less than 70 people in the eighth grade: 21x15 + 99x12 = 1503, 49x15 + 71x12 = 1587, so the total money to buy separately should be in this range, and 1575 is in, so the assumption is correct, so the total number of people exceeds 100

Set the seventh grade for x people.

15x+(120-x)x12=1575

x=45 The number of 8th graders is 120-45=752, and the washing machine of type A is x.

13%x+(x+500)13%=315

x= type b.

Xiao Li: +

(1) More than 100 people.

1080 is both an integer multiple of 12 and an integer multiple of 9 1080 alone cannot be determined, if the total number of people does not exceed 100, respectively, the number of tickets and purchases are 20% off in the eighth grade, then 1575-1080 = 455 455 should be the difference between the unit price of 15 yuan and the unit price of 12 yuan in the seventh grade, 455 is not an integer multiple of 15-12, so the number of people is not not more than 100, but more than 100

2) Let the number of 7th graders x the number of 8th graders y then 15x+12y=15759(x+y)=1080

The solution is x=45 y=75

45 in 7th grade and 75 in 8th grade.

2 Set the washing machine of type A to be $x.

13%x+(x+500)13%=315

x= type b is Xiao Li:

(1) More than 100, the ticket price per person is 9 yuan, 1080 9 = 120, according to the title, there are no less than 20 people in the seventh grade, and no less than 70 people in the eighth grade: 21x15 + 99x12 = 1503, 49x15 + 71x12 = 1587, so the total money bought separately should be in this range, and 1575 is in, so the assumption is correct, so the total number of people exceeds 100

2) Let the number of 7th graders x the number of 8th graders y then 15x+12y=15759(x+y)=1080

The solution is x=45 y=75

2 Set the washing machine of type A to be $x.

13%x+(x+500)13%=315

x=b type is Lee:

Qingdao edition of math workbook 69 pages of answers.

Let the cylinder volume unit 1, then the water injection speed is 1 5, the water discharge speed is 1 10, and the time t is set, then the column equation t*1 5-t*1 10=1, and t=10 minutes is obtained.