Solve the equation detailed process 2x 4 2y 2 4 6x 6x 6y 6z

Let the original grass on each acre of land be A, the grass growing every week is B, and the grass eaten by each cow per week is C, then: the total amount of grass on 2 acres of land eaten by 3 cows in 2 weeks is 2A+2*2B=2A+4B; Grass eaten per cow per week (a+2b) 3.

The total amount of grass on 2 acres of land eaten by 2 cows in 4 weeks is 2a+4*2b=2a+8b; Grass eaten per cow per week (a+4b) 4.

So: (a+2b) 3=(a+4b) 4;

a=4b, i.e., the amount of grass eaten by each cow per week is c=2b

In 6 weeks, there is a total of grass 6a + 6 * 6 b = 6a + 36b = 24b + 36b = 60b on 6 acres of land;

So the number of cattle is: (60b) (6*2b) = 5.

This problem can be set up by the auxiliary element method.

Let the original grass on every 2 acres of land be A, the new grass that grows in 2 weeks on every 2 acres of land is B, the grass that each cow can eat in 2 weeks is X, and Y cows can eat the original grass on 6 acres of land and the new grass that grows during this period in 6 weeks.

3x=a+b

2x=a+2b

Therefore x=ba=2b

Finally, y·3x=3a+3·3·b

i.e. xy=a+3b

by=2b+3b

y = 5, so it takes 5 cows to eat the original grass and the new grass that grows in 6 acres in 6 weeks.

The solution of the two equations is the same, both are x=1, y=2;

The general form of such equations is: ax+(a+1)y=a+2(1), (a+3)x+(a+4)y=a+5(2)(2)—(1) get: x+y=1

3),2)+(1) obtains: (2a+3)x+(2a+5)y=2a+7 simplification 2a(x+y)+3x+5y=2a+7, that is, 3x+5y=7(4) from (3), (4) obtains: x=—1, y=2

Sorry, a minus sign was dropped, it should be: the solution of the two equations is the same, both are x=-1, y=2;

The general form of such equations is: ax+(a+1)y=a+2(1), (a+3)x+(a+4)y=a+5(2)(2)—(1) get: x+y=1

3),2)+(1) obtains: (2a+3)x+(2a+5)y=2a+7 simplification 2a(x+y)+3x+5y=2a+7, that is, 3x+5y=7(4) from (3), (4) obtains: x=—1, y=2

Sorry, a minus sign was dropped, it should be: the solution of the two equations is the same, both are x=-1, y=2;

The general form of such equations is: ax+(a+1)y=a+2 (1), (a+3)x+(a+4)y=a+5 (2).

2)—(1) obtain: x+y=1 (3), (2)+(1) obtain: (2a+3)x+(2a+5)y=2a+7 simplify 2a(x+y)+3x+5y=2a+7, i.e., 3x+5y=7 (4).

From (3) and (4), we get: x=—1, y=2

The solution of the two equations is the same, both are x=1, y=2;

The general form of such equations is: ax+(a+1)y=a+2 (1), (a+3)x+(a+4)y=a+5 (2).

2)—(1) obtain: x+y=1 (3), (2)+(1) obtain: (2a+3)x+(2a+5)y=2a+7 simplify 2a(x+y)+3x+5y=2a+7, i.e., 3x+5y=7 (4).

From (3) and (4), we get: x=—1, y=2

Substituting x=2y+6 into (x-2) +y=4

Get. 2y+6-2)²+y²=4

i.e., no friend (2y+4) +y =4

5y + 16y + 12 = 0

i.e. (5y+6)(y+2)=0

So y= -6 5 or socks answer -2

and x=2y+6=18 5 or 2

1：2x-y=

x-2y = equation 1 * 2 minus the equation Liang calendar 2 to get 4x-2y-x + 2y = 9, that is, 3x=9, x=3, get y=2x-5=1

2: Ditto, multiply Equation 1 by 2 and subtract Equation 2 to get 14x+6y+5x-6y=19, 19x=19, x=1

3y=5-7x=-2,y=-2/3

Multiply both sides of the first equation by 2 and add the second equation to get x=-5, and then bring it into one of the equations to get y=3 2

Solution: 4x -9y = 15 (1).

2x-3y=5 (2)

1) Deformation: (2x+3y)(2x-3y)=15(2) substitution (1)5(2x-3y)=15

2x+3y=3 (3)

x=2[(3)-(2)]/6

y=-1/3

x=2 y=-1/3

That's the full answer.