The system of equations in the first year of mathematics is in a hurry!

This question is still very simple! Since Xiao Ming regards -3 as 3, then it is enough to substitute the solution he made into the wrong equation, and there is 3a+6b=c(1), 3a-6b=3; Xiao Gang misunderstood the number in equation (1), but the solution he made must make the original equation (2) hold, then there is 5a-18b=-3(3). Finally, if you connect the three formulas listed above, you can solve the three unknowns!

The result is a=; b=;c=6

Solution: Substituting x=3, y=6 into the original system of equations, obtains.

3a+6b=c①

3a-6b=3, 6a=3+c

c=6a-3

Substituting x=5, y=18 into the original system of equations, obtain.

5a+18b=6a-3

5a-18b=-3

.Then do the math yourself.

Do you see b as six? In this way: from Xiao Ming to get 3a-6b=3 3a+6b=c by adding the two formulas to get 6a=3+c from Xiao Li to get 5a+108=c and the above equation 6a=3+c to form a group, the solution is a=-105 c=-413 and substitute ac into 3a+6b=c to get b=-(49 3).

1) The value of b in the equation is: x=5 ?? What do you mean?

Since the same solution, then 2x+5y=-6 3x-5y=16 can form a system of equations. Solution:

x=2,y=-2

Substituting in, we get: 2a+4b=-4,2b+2b=-8 This system of equations gets: b=-2, a=2

First, the values of x and y are obtained by combining the two equations with coefficients.

Substituting the other two equations, synapsing the system of equations about a and b, we can solve the values of a and b. Then you can ask for it.

Solution: (x+y 4)-(x-y 5)+(x+y 4)+(x-y 5)=-1+3

2(x+y/4)=2

x+y has not changed 4) = 1

then (x-y 5) = 2

x+y/4=1

Column {x-y 5=2

After that, the average person will be.,If you won't, just look at the empty code!!

Solution: x+y 4-x+y 5=-1

y/4+y/5=-1

5y+4y=-20

9y=-20

y=-9/20

x just bring it in and calculate, maybe the value may be wrong in the calculation process, so you can't copy it directly!! Write according to the format and method and you will get the answer!

What does the second question mean, is y=3 or is this a formula? It's a bit messy, as for the third question, I don't understand the meaning to explain it clearly! Judgment !! Let's follow up, and after answering, it's hard work!!

Please be a little more detailed, too messy or one by one out.

In the first question, add the two equations to get 7 = 14, x = 2, and then substitute 2 into the above equation: 8 + y = 9, y = 1

The second question also uses the method of addition and subtraction.

2x+5y=-6①

3x-5y=16 ②

②5x=10

x=2 substitution: 2 2+5y=-6

5y=-10

y=-2x=2 y=-2 substituting ax-by=-4 :2a+2b=-4 x=2 y=-2 substituting bx+ay=-8:2b-2a=-8 +4b=-12

b=-3 substitution: 2a-2 (-3)=-4

2a=2a=1

a=1 b=-3 substitution (2a+b)2004:(2a+b)2004=(2 1-3)2004=-2004

The value of 2a+b)2004 is -2004.

This means that we can first find the two equations 2x+5y=-6 and 3x-5y=16 to get x=2 and y=-2

Substituting x=2 and y=-2 into the other 2 equations yields.

2a+2b=-4

2b-2a=-8

a=1,b=-3

2a+b)2004=-2004

3x-5y=2a

2x+7y=a-18

If the solution is the opposite number, then y=-x

Substituting the original system of equations, we get:

3x+5x=2a

2x-7x=a-18

x=a/4x=(18-a)/5

a 4=(18-a) before selling 5

5a=4(18-a)

5a=72-4a

9a=72a=8

x=a/4=2

y=-x=-2

2x-5y+13=0 ①

9x+6y-8=0 ②

18x-45y+117-18x-12y+16=0-045y-12y +133 =0

57y=-133

y=7 3 substitute y=7 3 into the middle of the conjecture:

2x-35/3+13=0

2x=35/3 -13

2x=-4/3

x=-2/3

So x=-2 3 y=7 3 is the solution of the original system of equations.

Question 1: 31x=19a-90 31y=-a-54

Because x and y are opposite to each other, the observed circle is 18a-144=0 a=8

Question 2: There is a problem with one of the equations, please write it clearly.

First, calculate the values of x and y, and solve x=2 and y=1

Then, substituting the values of x and y into mx ny=8 and mx ny=4 gives 2m+n=82m-n=4

The solution yields m=3 and n=2