For the problem of binary linear equations, 20 points are added

x/2-y/3=2………1）

2x-3y=28………2）

1) 12, got:

6x-4y=24………3）

2) 3, got:

6x-9y=84………4）

3)-(4), get:

5y=-60

y=-12 is substituted into (2) to get:

2x-3*（-12）=28

2x+36=28

2x=-8x=-4

The solution of the system of equations is:

x=-4y=-12

m/2+n/3=13………1）

m/3-n/4=3………2）

1) 24, got:

12m+8n=312………3）

2) 36, got:

12m-9n=108………4）

3)-(4), get:

17n=204

n = 12 substituted into (1), get:

m/2+12/3=13

m/2+4=13

m/2=9m=18

The solution of the system of equations is:

m=18n=12

1.{x 2-y 3=2 multiply both sides by 6,3x-2y=12 2x-3y=28 ,5x-5y=40 x-y=8 ,2 ,-y=12,y=-12,x=-4

2.{m 2 + n 3=13 multiply by 3 on both sides at the same time, m 3-n 4=3 multiply by 4 on both sides at the same time, (4 3)m-n=12 +17 6)m=51 17m=306 m=18 substitute ,,n=12

x=3,y=4 to be a1x+b1y=c1,a2x+b2y=c2, there are 3a1+4b1=c1

3a2+4b2=c2,4, directly so that 3x=m 2y=n is the same solution as the original equation, so that the solution of the latter equation is x=1 y=2,2, {ax+by=c {2ax+2by=2c substitute x= into 3a+4b=c ..1,x=3,y=4 to be a1x+b1y=c1,a2x+b2y=c2,yes.

3a1+4b1=c1

3a2+4b2=c2 (1)

3a1x+2b1y=5c1

3a2x+2b2y=5c2

On both sides of the equation divided by 5 there is:

3/5a1x+2/5b1y=c1

3/5a2x+2/5b2y=c2 (2)

Compare the equations (1) and (2) of the Minshan group

There are 3x 5 3 2y 5 4

So x 5,y with a guess of 10,0, a difficult problem about the stupid type of binary linear equations, urgent. Resolved within 30 minutes.

It is known that the system of binary linear equations a1x+b1y=c1; The solution of a2x+b2y=c2 is: x=3, y=4Finding the system of equations: 3a1x+2b1y=c1; Solution of 3a2x+2b2y=c2?

It seems that it is very rare to rummage through the workbook or something.

(3) 2x = 3x, 2x = 3, x = 2 3 (4) x + 1 = 2 , x = 1 or x = -3 (5) 2 (x - 1) = 8, (x - 1) = 4, x - 1 = 2, x = 3 or x = 1 (6) 6 (x - 3) = 18, (x - 3) = 3, x - 3 - root number 3, x = 3 + root number 3 or x = 3 - root number 3 (7) (x + 2) (x + 3) = 0, x + 2 = 0 or x + 3 = 0, x = -2 or x = -3 (8) (x - 3) (x-8) =0, x-3=0 or x-8=0, x=3 or x=8(9)(x+2) =0, x+2=0, x=-2(10)x +x-1+5 4=5 4,(x+1 2) =5 4,x+1 2= root number 5 2, x=1 + root number 5 2 or x=1 - root number 5 2 (11) x +4x-5 + 9 = 9, (x+2) = 9, x+2 = 3, x=1 or x=-5(12) (x+3)(x-2)=0, x+3=0 or x-2=0, x=-3 or x=2

Solution: Let the distance of the correspondent reach a certain place be x kilometers, and the original time is y hours, according to the topic:

x/15=y-24/60

x/12=y+15/60

Solving the system of equations yields: x=39; y=3

Answer: The distance traveled by the correspondent to a certain place is 39 kilometers; The original time was 3 hours?

Solution: Let the distance x, the original time y.

XY+ equation you can solve it yourself, the equation must be right, it is too annoying to solve it...