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:
 
9
5
x + y + z = 400    (1)
 
17
20
x + 
17
10
y + 
17
5
z = 400    (2)
 x = 92    (3)
Question solving process:

Multiply both sides of equation (1) by 17
Divide the two sides of equation (1) by 36, the equation can be obtained:
         
17
20
x + 
17
36
y + 
17
36
z = 
1700
9
    (4)
, then subtract both sides of equation (4) from both sides of equation (2), the equations are reduced to:
 
9
5
x + y + z = 400    (1)
 
221
180
y + 
527
180
z = 
1900
9
    (2)
 x = 92    (3)

Multiply both sides of equation (1) by 5
Divide the two sides of equation (1) by 9, the equation can be obtained:
         x + 
5
9
y + 
5
9
z = 
2000
9
    (5)
, then subtract both sides of equation (5) from both sides of equation (3), the equations are reduced to:
 
9
5
x + y + z = 400    (1)
 
221
180
y + 
527
180
z = 
1900
9
    (2)
5
9
y 
5
9
z = 
1172
9
    (3)

Multiply both sides of equation (2) by 100
Divide the two sides of equation (2) by 221, the equation can be obtained:
         
5
9
y + 
155
117
z = 
190000
1989
    (6)
, then add the two sides of equation (6) to both sides of equation (3), the equations are reduced to:
 
9
5
x + y + z = 400    (1)
 
221
180
y + 
527
180
z = 
1900
9
    (2)
 
10
13
z = 
7668
221
    (3)

Multiply both sides of equation (3) by 6851
Divide both sides of equation (3) by 1800, get the equation:
         
527
180
z = 
6603
50
    (7)
, then subtract both sides of equation (7) from both sides of equation (2), get the equation:
 
9
5
x + y + z = 400    (1)
 
221
180
y = 
154427
450
    (2)
 
10
13
z = 
7668
221
    (3)

Multiply both sides of equation (3) by 13
Divide both sides of equation (3) by 10, get the equation:
         z = 
3834
85
    (8)
, then subtract both sides of equation (8) from both sides of equation (1), get the equation:
 
9
5
x + y = 
37834
85
    (1)
 
221
180
y = 
154427
450
    (2)
 
10
13
z = 
7668
221
    (3)

Multiply both sides of equation (2) by 180
Divide both sides of equation (2) by 221, get the equation:
         y = 
23758
85
    (9)
, then subtract both sides of equation (9) from both sides of equation (1), get the equation:
 
9
5
x = 
828
5
    (1)
 
221
180
y = 
154427
450
    (2)
 z = 
3834
85
    (3)

The coefficient of the unknown number is reduced to 1, and the equations are reduced to:
 x = 92    (1)
 y = 
23758
85
    (2)
 z = 
3834
85
    (3)


Therefore, the solution of the equation set is:
x = 92
y = 
23758
85
z = 
3834
85


Convert the solution of the equation set to decimals:
x = 92
y = 279.505882
z = -45.105882

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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