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:
 7x + 15y + 55z = 14    (1)
 15x + 55y + 225z = 30    (2)
 55x + 225y + 979z = 122    (3)
Question solving process:

Multiply both sides of equation (1) by 15
Divide the two sides of equation (1) by 7, the equation can be obtained:
         15x + 
225
7
y + 
825
7
z = 30    (4)
, then subtract both sides of equation (4) from both sides of equation (2), the equations are reduced to:
 7x + 15y + 55z = 14    (1)
 
160
7
y + 
750
7
z = 0    (2)
 55x + 225y + 979z = 122    (3)

Multiply both sides of equation (1) by 55
Divide the two sides of equation (1) by 7, the equation can be obtained:
         55x + 
825
7
y + 
3025
7
z = 110    (5)
, then subtract both sides of equation (5) from both sides of equation (3), the equations are reduced to:
 7x + 15y + 55z = 14    (1)
 
160
7
y + 
750
7
z = 0    (2)
 
750
7
y + 
3828
7
z = 12    (3)

Multiply both sides of equation (2) by 75
Divide the two sides of equation (2) by 16, the equation can be obtained:
         
750
7
y + 
28125
56
z = 0    (6)
, then subtract both sides of equation (6) from both sides of equation (3), the equations are reduced to:
 7x + 15y + 55z = 14    (1)
 
160
7
y + 
750
7
z = 0    (2)
 
357
8
z = 12    (3)

Multiply both sides of equation (3) by 2000
Divide both sides of equation (3) by 833, get the equation:
         
750
7
z = 
24000
833
    (7)
, then subtract both sides of equation (7) from both sides of equation (2), get the equation:
 7x + 15y + 55z = 14    (1)
 
160
7
y = 
24000
833
    (2)
 
357
8
z = 12    (3)

Multiply both sides of equation (3) by 440
Divide both sides of equation (3) by 357, get the equation:
         55z = 
1760
119
    (8)
, then subtract both sides of equation (8) from both sides of equation (1), get the equation:
 7x + 15y = 
94
119
    (1)
 
160
7
y = 
24000
833
    (2)
 
357
8
z = 12    (3)

Multiply both sides of equation (2) by 21
Divide both sides of equation (2) by 32, get the equation:
         15y = 
2250
119
    (9)
, then subtract both sides of equation (9) from both sides of equation (1), get the equation:
 7x = 
308
17
    (1)
 
160
7
y = 
24000
833
    (2)
 z = 
32
119
    (3)

The coefficient of the unknown number is reduced to 1, and the equations are reduced to:
 x = 
44
17
    (1)
 y = 
150
119
    (2)
 z = 
32
119
    (3)


Therefore, the solution of the equation set is:
x = 
44
17
y = 
150
119
z = 
32
119


Convert the solution of the equation set to decimals:
x = 2.588235
y = -1.260504
z = 0.268908

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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