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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:
 A + B + C + D = 47    (1)
 B -3D = 0    (2)
 A -1C = 3    (3)
 8A -11B -16D = 2    (4)
Question solving process:

Subtract both sides of equation (1) from both sides of equation (3) ,the equations are reduced to:
 A + B + C + D = 47    (1)
 B -3D = 0    (2)
-1B -2C -1D = -44    (3)
 8A -11B -16D = 2    (4)

Multiply both sides of equation (1) by 8, the equation can be obtained:
         8A + 8B + 8C + 8D = 376    (5)
, then subtract both sides of equation (5) from both sides of equation (4), the equations are reduced to:
 A + B + C + D = 47    (1)
 B -3D = 0    (2)
-1B -2C -1D = -44    (3)
-19B -8C -24D = -374    (4)

Add both sides of equation (2) to both sides of equation (3) ,the equations are reduced to:
 A + B + C + D = 47    (1)
 B -3D = 0    (2)
-2C -4D = -44    (3)
-19B -8C -24D = -374    (4)

Multiply both sides of equation (2) by 19, the equation can be obtained:
         19B -57D = 0    (6)
, then add the two sides of equation (6) to both sides of equation (4), the equations are reduced to:
 A + B + C + D = 47    (1)
 B -3D = 0    (2)
-2C -4D = -44    (3)
-8C -81D = -374    (4)

Multiply both sides of equation (3) by 4, the equation can be obtained:
        -8C -16D = -176    (7)
, then subtract both sides of equation (7) from both sides of equation (4), the equations are reduced to:
 A + B + C + D = 47    (1)
 B -3D = 0    (2)
-2C -4D = -44    (3)
-65D = -198    (4)

Multiply both sides of equation (4) by 4
Divide both sides of equation (4) by 65, get the equation：
        -4D = - 
792
65
    (8)
, then subtract both sides of equation (8) from both sides of equation (3), get the equation：
 A + B + C + D = 47    (1)
 B -3D = 0    (2)
-2C = - 
2068
65
    (3)
-65D = -198    (4)

Multiply both sides of equation (4) by 3
Divide both sides of equation (4) by 65, get the equation：
        -3D = - 
594
65
    (9)
, then subtract both sides of equation (9) from both sides of equation (2), get the equation：
 A + B + C + D = 47    (1)
 B = 
594
65
    (2)
-2C = - 
2068
65
    (3)
-65D = -198    (4)

Divide both sides of equation (4) by 65, get the equation：
        -1D = - 
198
65
    (10)
, then add the two sides of equation (10) to both sides of equation (1), get the equation：
 A + B + C = 
2857
65
    (1)
 B = 
594
65
    (2)
-2C = - 
2068
65
    (3)
-65D = -198    (4)

Divide both sides of equation (3) by 2, get the equation：
        -1C = - 
1034
65
    (11)
, then add the two sides of equation (11) to both sides of equation (1), get the equation：
 A + B = 
1823
65
    (1)
 B = 
594
65
    (2)
-2C = - 
2068
65
    (3)
 D = 
198
65
    (4)

Subtract both sides of equation (2) from both sides of equation (1), get the equation：
 A = 
1229
65
    (1)
 B = 
594
65
    (2)
 C = 
1034
65
    (3)
 D = 
198
65
    (4)

The coefficient of the unknown number is reduced to 1, and the equations are reduced to：
 A = 
1229
65
    (1)
 B = 
594
65
    (2)
 C = 
1034
65
    (3)
 D = 
198
65
    (4)


Therefore, the solution of the equation set is:
A = 
1229
65
B = 
594
65
C = 
1034
65
D = 
198
65


Convert the solution of the equation set to decimals:
A = 18.907692
B = 9.138462
C = 15.907692
D = 3.046154

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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