It is known that the system of equations about XY is 2x + 3Y = - 53x + 7Y = M. when - 20 < m ＜ - 10, there is an integer solution, then x? + XY + y=________

It is known that the system of equations about XY is 2x + 3Y = - 53x + 7Y = M. when - 20 < m ＜ - 10, there is an integer solution, then x? + XY + y=________

The solution of the equations is x = - 7-3m / 5, y = 3 + 2m / 5
∵ when - 20 ﹤ m ﹤ 10, there is an integer solution
∴m=-15,,x=2,y=-3
∴x²+xy+y²=4-6+9=7

Solve the following equations {3x + 7Y = 6,2x-7y = 4; (2) {y = 3x, 2x + 3Y = 22

1、 One copy plus two formula: 3x + 7Y + 2x-7y = 10
5X=10 X=2
X = 2 into 3 * 2 + 7Y = 6, y = 0
2、 One copy is substituted into two formulas: 2x + 3 * 3x = 2211x = 22x = 2
X = 2 into the form: y = 3 * 2, y = 6

It is known that M is an integer and - 60 Math homework help users 2016-11-25 report Use this app to check the operation efficiently and accurately!

2x-3y=-5,
-3x-7y=m
That is, y = - (2m-15) / 23
-60 ＜ m ＜ - 30, that is - 135 ＜ 2m-15 ＜ - 75, which is a multiple of 23, and 2m-15 is an odd number
So 2m-15 = - 23 * 5 = - 115, that is, M = - 50
So y = 5, x = 5
m=-50,x^2+y=5^2+5=30

It is known that M is an integer and - 60 is less than m and less than - 30. There are integer solutions to the binary linear equations 2x-3y = - 5 and - 3x-7y = m of X

2x-3y = - 5 ① and - 3x-7y = m ② have integer solutions
By eliminating ① × 3 + ② × 2, we can get
-23y=-15+2m
∵ m is an integer and - 60 ﹤ m ﹤ 30
∴-135＜-15+2m＜-75
That is - 135 ＜ - 23y ＜ - 75
135/23＞y＞75/23
And ∵ the equations have integer solutions
ν y = 4 or 5
Substitute 2x-3y = - 5
When y = 4, x = 7 / 2 (round)
When y = 5, x = 5
Then the square of X. + y = 52 + 5 = 30

It is known that the system of bivariate first-order equations on XY is 3x + 5Y = m + 2,2x + 3Y = m and X + y = 2

3x+5y=m+2 (1)
2x+3y=m (2)
(1)-(2)
x+2y=2
x+y=2
x=2 y=0
M=4

If the solution of the equations 3x + 2Y = m + 1,2x + y = M-1 for XY satisfies X-Y > 0, find the value range of M

3x+2y=m+1 （1）
2x+y=m-1 （2）
(2) X 2 - (1) gives x = m-3
Results y = 5-m was obtained by substituting (2)
Because X-Y > 0
So m-3-5 + m > 0
M > 4
A: M > 4

If we know the solution XY > 0 of the system of equations {x + 2Y = m, 2x-y = 3M + 1 about X and y, then the value of M is

(x+2y)+2(2x-y)=m+2(3m+1)
That is, 5x = 7m + 2
-2(x+2y)+(2x-y)=-2m+(3m+1)
That is - 5Y = m + 1
Then xy = [(7m + 2) / 5] × [(M + 1) / (- 5)] = - (7m + 2) (M + 1) / 25 > 0
Then (7m + 2) (M + 1)

In the equation system {2x + y = 1-k x + 2Y = 2}, if the unknown number XY satisfies that x + y is greater than 0., then the value range of K is·

2x+y=1-k
x+2y=2
Add up
3x+3y=3-k
x+y>0
So 3x + 0
So 3-K > 0
So K

It is known that the solution XY of the system of equations 2x + y = 3M and X + 2Y = M-1 is opposite to each other to find the value of M

Because x, y are opposite numbers
So y = - X
（2x+y)+(x+2y)=(3m)+(m-1)
3x+3y=4m-1
3x+3(-x)=4m-1
0=4m-1
4m=1
m=1\4

Known equations 2x−y＝4m+3 The solution X and y of 2Y − x = − 3 are opposite numbers to each other, and the value of M is calculated

From the meaning of the title
2x−y＝4m+3
2y−x＝−3
x+y＝0 ，
(1) + 2
y＝−1
x＝1 ，
By substituting (1), M = 0