What is the value of m The system of equations 2x 7y m 18 3x 5y 2m is the opposite of each other, an

2x+7y=m-18 3x-5y=2m solution: 3- 2 gets: 31y=-m-18 solution gets y= (-m-18) 31

5 + 7 gets: 31x=19m-90 solution gets x= (19m-90) 31 is obtained by the opposite number of the solutions of the system of equations: x+y=0

That is, (-m-18) 31+(19m-90) 31=0m-18+19m-90=0

18m=108

m=6When m=6, x=24 31,y=-24 31, so the solution of the original system of equations is x=24 31,y=-24 31

Solution: 2x+7y=m-18··· 3x-5y=2m··· 3：6x+21y=3m-54

2：6x-10y=4m

Subtracting these two equations yields: 31y=-m-54

5：10x+35y=5m-90

7：21x-35y=14m

Add these two formulas to yield: 31x=19m-90

x y is the opposite of each other.

x=-y,x+y=0,31x+31y=0

19m-90-m-54=0

Solution: m=8

31y=-8-54,y=-2

31x=19×8-90，x=2

In summary, m=8, the solution of the system of equations is x=2, y=-2

x and y are inverses of each other: y=-x

2x+7(-x)=m-18

5x=m-18

x=(18-m)/5

3x-5(-x)=2m

8x=2mx=m/4

18-m)/5=m/4

18*4-4m=5m

9m=18*4

When m=8m is 8, the solutions of the equation system 2x+7y=m-18 3x-5y=2m are opposite to each other.

2x+7y=8-18

2x+7y=-10...1)

3x-5y=2*8

3x-5y=16...2)

1)*5+(2)*7:10x+21x=-50+11231x=62

x=2 substitution(1): 2*2+7y=-10

7y=-14

y=-2

Solution: 3x-5y=2m(1).

2x+7y=m-18 （2）

2)*2 gets: 4x+14y=2m-36(3)3)-(1)gets:x+19y=-36(4).

The solutions of systems of equations are opposite to each other.

x+y=0, i.e., x=-y(5).

Substitute (5) into (4), 18y=-36

y=-2x=2

3*2-5*(-2)=2m

m=8 six degrees of well-known group] team to answer for you, satisfaction, thank you.

The system of equations "cannot be made into "opposite numbers".

x－5y=2m ①

2x＋7y=m－18 ②

Put the game regret equation 2 to get.

10y－7y=4m－m＋18

17y=3m＋18

y=－（3m＋18）/17

Put the equation 7 5 to get.

7x＋10x=14m＋5m－90

17x=19m－90

x=（19m－90）/17

Because x and y are inverse numbers to each other, 19m 90) 17 (3m 晌lamin 18) 17=0

19m－90－3m－18=0

16m=108m=8

x-5y=2m,2x+7y=m-18,—》x=(19m-90) 17,y=(-3m-18) 17,x,y are opposite numbers to each other,—》x+y=(19m-90) 17+(-3m-18) 17=0,silver reputation base—》m=27 4,—xuru" x=9 4,y=-9 4. Sharp.

If the solution of the leaky wheel of the system of return letter equations is the inverse number of phase.

Then x=-y so.

6y=2m5y=m-18

The solution is m=9 4

If the solution is the opposite of the burning code, then y=-x is substituted into the equation.

3x-5y=2m

2x+7y=m-18

Get. 3x+5x=2m

2x-7x=m-18

Get. 8x=2m

5x=m-18

Relieved of lead. m=8

3x-5y=16

2x+7y=-10

Xie Lao Duan is very good.

x=2 ,y=-2

If y=-x is the opposite of each other, then y=-x is the equation 3x-5y=2m 2x+7y=m-18 to get 3x+5x=2m 2x-7x=m-18 to get 8x=2m -5x=m-18 to solve m=8 3x-5y=16 2x+7y=-10 to get x=2, y=-2

3x-5y=2m (1)

2x+7y=m-1 (2)

The solutions are inverse numbers of each other.

y=-xSubstituting y=-x into the original equation yields:

3x+5x=2m (3)

2x-7x=m-1 (4)

i.e.: 4x=m (5).

5x=m-1 (6)

5) *5 + (4) * 4 get:

0=5m+4m-4

9m-4=0

m=4/9

m=4/9

Solution: 3x-5y=2m(1).

2x+7y=m-1 (2)

The solutions are inverse numbers of each other.

y=-xSubstituting y=-x into the original equation yields:

3x+5x=2m (3)

2x-7x=m-1 (4)

i.e.: 4x=m (5).

5x=m-1 (6)

5) *5 + (4) * 4 get:

5m+4m-4=0

9m-4=0

m=4/9

Solution: If the solutions of the equation are opposites, then x+y=0.

From 3x-5y=m-18, 3x+3y-3y-5y=m-18, y=(18-m) 8 can be deduced.

From 4m+7y=m-18, 7x+7y-7x=-(3m+18) can be deduced, and x=(3m+18) 7 is obtained

From x+y=0, so (18-m) 8+(3m+18) 7=0 is solved to m=-(270 17).

Solution: Solve this system of equations, get.

x=(19m-90)/31

y=-(m+54)/31

Since the solutions of this system of equations are opposite to each other, x+y=0 can be obtained. m=8

When m=8, x=2

y=-2 so the solution of the original system of equations is {

x=2y=-2

Satisfied, I don't know how to ask.

Because :x and y are opposite numbers to each other, so:x=-y; Substitute x-5y=2m.

y-5y=2m, obtain: m=-3y......(1)；Substitute m=-3y and x=-y into 2x+7y=m-18.

Get: -2y+7y=-3y-18

Solution: y=-9 4 then: x=

y = thus, m = 3y = -3 (-9 4).

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