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On line solution of multivariate equations：
    First set the elements of the equation (i.e. the number of unknowns), then click the "Next" button to enter the coefficients of each element of the equation set, and click the "Next" button to obtain the solution of the equation set.
    Note that the coefficients of each element of the equation system can only be numbers, not algebraic expressions (including mathematical functions).
    Current location：Equations > Multivariate equations > Answer
detailed information：
The input equation set is:
 6A -5B -2C + 4D = 0    (1)
 3A -10B -6C + 3D = 180    (2)
 3A -5B + 2C = 0    (3)
 A -5B + 4D = 0    (4)
Question solving process:

Divide the two sides of equation (1) by 2, the equation can be obtained:
         3A - 
5
2
B -1C + 2D = 0    (5)
, then subtract both sides of equation (5) from both sides of equation (2), the equations are reduced to:
 6A -5B -2C + 4D = 0    (1)
- 
15
2
B -5C + D = 180    (2)
 3A -5B + 2C = 0    (3)
 A -5B + 4D = 0    (4)

Divide the two sides of equation (1) by 2, the equation can be obtained:
         3A - 
5
2
B -1C + 2D = 0    (6)
, then subtract both sides of equation (6) from both sides of equation (3), the equations are reduced to:
 6A -5B -2C + 4D = 0    (1)
- 
15
2
B -5C + D = 180    (2)
- 
5
2
B + 3C -2D = 0    (3)
 A -5B + 4D = 0    (4)

Divide the two sides of equation (1) by 6, the equation can be obtained:
         A - 
5
6
B - 
1
3
C + 
2
3
D = 0    (7)
, then subtract both sides of equation (7) from both sides of equation (4), the equations are reduced to:
 6A -5B -2C + 4D = 0    (1)
- 
15
2
B -5C + D = 180    (2)
- 
5
2
B + 3C -2D = 0    (3)
- 
25
6
B + 
1
3
C + 
10
3
D = 0    (4)

Divide the two sides of equation (2) by 3, the equation can be obtained:
        - 
5
2
B - 
5
3
C + 
1
3
D = 60    (8)
, then subtract both sides of equation (8) from both sides of equation (3), the equations are reduced to:
 6A -5B -2C + 4D = 0    (1)
- 
15
2
B -5C + D = 180    (2)
 
14
3
C - 
7
3
D = -60    (3)
- 
25
6
B + 
1
3
C + 
10
3
D = 0    (4)

Multiply both sides of equation (2) by 5
Divide the two sides of equation (2) by 9, the equation can be obtained:
        - 
25
6
B - 
25
9
C + 
5
9
D = 100    (9)
, then subtract both sides of equation (9) from both sides of equation (4), the equations are reduced to:
 6A -5B -2C + 4D = 0    (1)
- 
15
2
B -5C + D = 180    (2)
 
14
3
C - 
7
3
D = -60    (3)
 
28
9
C + 
25
9
D = -100    (4)

Multiply both sides of equation (3) by 2
Divide the two sides of equation (3) by 3, the equation can be obtained:
         
28
9
C - 
14
9
D = -40    (10)
, then subtract both sides of equation (10) from both sides of equation (4), the equations are reduced to:
 6A -5B -2C + 4D = 0    (1)
- 
15
2
B -5C + D = 180    (2)
 
14
3
C - 
7
3
D = -60    (3)
 
13
3
D = -60    (4)

Multiply both sides of equation (4) by 7
Divide both sides of equation (4) by 13, get the equation：
         
7
3
D = - 
420
13
    (11)
, then add the two sides of equation (11) to both sides of equation (3), get the equation：
 6A -5B -2C + 4D = 0    (1)
- 
15
2
B -5C + D = 180    (2)
 
14
3
C = - 
1200
13
    (3)
 
13
3
D = -60    (4)

Multiply both sides of equation (4) by 3
Divide both sides of equation (4) by 13, get the equation：
         D = - 
180
13
    (12)
, then subtract both sides of equation (12) from both sides of equation (2), get the equation：
 6A -5B -2C + 4D = 0    (1)
- 
15
2
B -5C = 
2520
13
    (2)
 
14
3
C = - 
1200
13
    (3)
 
13
3
D = -60    (4)

Multiply both sides of equation (4) by 12
Divide both sides of equation (4) by 13, get the equation：
         4D = - 
720
13
    (13)
, then subtract both sides of equation (13) from both sides of equation (1), get the equation：
 6A -5B -2C = 
720
13
    (1)
- 
15
2
B -5C = 
2520
13
    (2)
 
14
3
C = - 
1200
13
    (3)
 
13
3
D = -60    (4)

Multiply both sides of equation (3) by 15
Divide both sides of equation (3) by 14, get the equation：
         5C = - 
9000
91
    (14)
, then add the two sides of equation (14) to both sides of equation (2), get the equation：
 6A -5B -2C = 
720
13
    (1)
- 
15
2
B = 
8640
91
    (2)
 
14
3
C = - 
1200
13
    (3)
 D = - 
180
13
    (4)

Multiply both sides of equation (3) by 3
Divide both sides of equation (3) by 7, get the equation：
         2C = - 
3600
91
    (15)
, then add the two sides of equation (15) to both sides of equation (1), get the equation：
 6A -5B = 
1440
91
    (1)
- 
15
2
B = 
8640
91
    (2)
 
14
3
C = - 
1200
13
    (3)
 D = - 
180
13
    (4)

Multiply both sides of equation (2) by 2
Divide both sides of equation (2) by 3, get the equation：
        -5B = 
5760
91
    (16)
, then subtract both sides of equation (16) from both sides of equation (1), get the equation：
 6A = - 
4320
91
    (1)
- 
15
2
B = 
8640
91
    (2)
 C = - 
1800
91
    (3)
 D = - 
180
13
    (4)

The coefficient of the unknown number is reduced to 1, and the equations are reduced to：
 A = - 
720
91
    (1)
 B = - 
1152
91
    (2)
 C = - 
1800
91
    (3)
 D = - 
180
13
    (4)


Therefore, the solution of the equation set is:
A = - 
720
91
B = - 
1152
91
C = - 
1800
91
D = - 
180
13


Convert the solution of the equation set to decimals:
A = -7.912088
B = -12.659341
C = -19.780220
D = -13.846154

解方程组的详细方法请参阅：《多元一次方程组的解法》
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