The problem of binary linear equations in the first grade of junior high school

Solution:1There are children x and apple y. According to the title:

1)6x-6=y

2)5x+5=y

Solution: x=11, y=60

After testing, it is in line with the topic.

A: There are 11 children and 60 apples.

2.Let the ten digits be x and the single digit be yAccording to the title:

1)x+y=9

2)(x+10y)-(10x+y)=9

Solution: x=4, y=5

After testing, it is in line with the topic.

A: Ten digits are 4 and single digits are 5

3.Let A have a speed of x kilometers per hour and B a speed of y kilometers per hour. According to the title:

1)2)2y+

Solution: x=3, y=5

After testing, it is in line with the topic.

A: A's speed is 3 kilometers per hour, and B's speed is 5 kilometers per hour.

4.(1)x=1,y=3.(2)x=4,y=1.

5.Let A deposit be $00,000 and B $10,000. According to the title:

1)x+y=20

2) Note: 9,500 yuan = 10,000 yuan).

Solution: x=5, y=15

After testing, it is in line with the topic.

A: A deposit is 50,000 yuan, and B deposit is 150,000 yuan.

6.There are brothers x people and sisters y people in this house. According to the title:

1)x-1=y

2)y-1=x/2

Solution: x=4, y=3

After testing, it is in line with the topic.

A: There are 4 brothers and 3 sisters in this family.

1: Set the children as x and the apples as y; Two equations can be established: (1) 6*x=y+6; (2)5*x=y-5;Solution: x=11; y=60;That is, there are 11 children and 60 apples.

2: Let the single digit be y and the ten digit be x, and the following two equations (1) x+y=9 can be obtained（2）10y+x-（10x+y）=9；The solution is x=4;y=5。

Due to time issues, there are only two problems.

1) Solution: Set up the original x people in the first workshop, and the original y people in the second workshop, then by the title:

x=4y/5-30，x+10=3(y-10)/4；

Namely. 5x-4y=-150……(1)

4x-3y=-70……(2)

1) *4 + (2) *5, got.

y=250 is substituted into (1), knowing that 5x-1000=-150, so x=170.

A: There were 170 people in the first workshop and 250 people in the second workshop.

2) Solution: There are x basketballs and Y volleyballs. By the title, x=2y-3, x:y=3:2 i.e. x=2y-3……(1)

2x=3y……(2)

Substituting (1) into (2) gives 4y-6=3y, so y=6.

Substituting (1), we get x=9.

A: There are 9 in basketball and 6 in volleyball.

3) Solution: It took x hours to ride a bicycle and Y hours to walk. From the title, x+y=15x+5y=20......(2)

2)-(1)*5,got.

10x=x=substitution(1), get y=.

A: It took 1 hour and 15 minutes to ride and 15 minutes to walk.

Solution: The student is x years old this year, and the teacher is y years old this year.

y+(y-x)=36 (When you were my age, I was 36 years old) x-(y-x)=0 (you were born when I was your age) x=12 y=24

Core or key point: y-x is the age difference between the two Grasp this point and do it.

Solution: Let A walk x kilometers and B walk y kilometers, then.

The solution is x=y=2, so the distance from point A to Beishan station is 2 km.

Draw a straight line.

Make use of the time-equal column of unary equations.

Note that when the car is picked up, it is car B going in the opposite direction.