Mathematics
         
语言:中文    Language:English
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:
 4x -5y + 5z = -39    (1)
 3x + 4y + 4z = 1    (2)
 4x -3y -4z = -4    (3)
Question solving process:

Multiply both sides of equation (1) by 3
Divide the two sides of equation (1) by 4, the equation can be obtained:
         3x 
15
4
y + 
15
4
z = 
117
4
    (4)
, then subtract both sides of equation (4) from both sides of equation (2), the equations are reduced to:
 4x -5y + 5z = -39    (1)
 
31
4
y + 
1
4
z = 
121
4
    (2)
 4x -3y -4z = -4    (3)

Subtract both sides of equation (1) from both sides of equation (3) ,the equations are reduced to:
 4x -5y + 5z = -39    (1)
 
31
4
y + 
1
4
z = 
121
4
    (2)
 2y -9z = 35    (3)

Multiply both sides of equation (2) by 8
Divide the two sides of equation (2) by 31, the equation can be obtained:
         2y + 
2
31
z = 
242
31
    (5)
, then subtract both sides of equation (5) from both sides of equation (3), the equations are reduced to:
 4x -5y + 5z = -39    (1)
 
31
4
y + 
1
4
z = 
121
4
    (2)
281
31
z = 
843
31
    (3)

Multiply both sides of equation (3) by 31
Divide both sides of equation (3) by 1124, get the equation:
        
281
1124
z = 
843
1124
    (6)
, then add the two sides of equation (6) to both sides of equation (2), get the equation:
 4x -5y + 5z = -39    (1)
 
31
4
y = 
8711
281
    (2)
281
31
z = 
843
31
    (3)

Multiply both sides of equation (3) by 155
Divide both sides of equation (3) by 281, get the equation:
        
1405
281
z = 
4215
281
    (7)
, then add the two sides of equation (7) to both sides of equation (1), get the equation:
 4x -5y = 
6744
281
    (1)
 
31
4
y = 
8711
281
    (2)
281
31
z = 
843
31
    (3)

Multiply both sides of equation (2) by 20
Divide both sides of equation (2) by 31, get the equation:
         5y = 
5620
281
    (8)
, then add the two sides of equation (8) to both sides of equation (1), get the equation:
 4x = 
1124
281
    (1)
 
31
4
y = 
8711
281
    (2)
 z = 
843
281
    (3)

The coefficient of the unknown number is reduced to 1, and the equations are reduced to:
 x = 
281
281
    (1)
 y = 
1124
281
    (2)
 z = 
843
281
    (3)


Therefore, the solution of the equation set is:
x = 
281
281
y = 
1124
281
z = 
843
281


Convert the solution of the equation set to decimals:
x = -1.000000
y = 4.000000
z = -3.000000

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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