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Solve the systems of equations:
3x+5y-2z=03
7x-47+8z=37
-4x-9y+z=7

1 Answer

5 votes

Final answer:

To solve the system of equations, we can use the method of elimination or substitution. By multiplying and subtracting the equations, we eliminate variables to determine their values. However, in this case, we find that the system is inconsistent or contradictory, meaning there is no solution.

Step-by-step explanation:

To solve the system of equations:

3x + 5y - 2z = 0

7x - 4y + 8z = 37

-4x - 9y + z = 7

We can use the method of elimination or substitution to find the values of x, y, and z.

Let's use the elimination method:

Multiply the first equation by 7, the second equation by 3, and the third equation by 4 to make the coefficients of x equal in the first two equations:

21x + 35y - 14z = 0

21x - 12y + 24z = 111

-16x - 36y + 4z = 28

Subtract the second equation from the first equation:

(21x + 35y -14z) - (21x - 12y + 24z) = 0 - 111

-47y - 38z = -111

Subtract twice the second equation from the third equation:

(-16x - 36y + 4z) - 2(21x - 12y + 24z) = 28 - 2(111)

13x - 60y - 44z = -194

Now we have two equations:

-47y - 38z = -111

13x - 60y - 44z = -194

Let's multiply the first equation by 13 and the second equation by -47 to make the coefficients of y equal:

-611y - 494z = -1443

-611y + 2820y + 2088z = 9121

Add the two equations:

(-611y - 494z) + (-611y + 2820y + 2088z) = -1443 + 9121

2326y + 1594z = 7678

Now we have two equations:

2326y + 1594z = 7678

13x - 60y - 44z = -194

Multiply the first equation by 44 and the second equation by 1594 to make the coefficients of z equal:

102344y + 70236z = 338712

20702x - 95640y - 70256z = -31076

Add the two equations:

(102344y + 70236z) + (20702x - 95640y - 70256z) = 338712 - 31076

20702x - 25404y = 307636

Now we have two equations:

20702x - 25404y = 307636

13x - 60y = -194

Multiply the second equation by -1692:

-1692(13x - 60y) = -1692(-194)

-1692(13x) - 1692(-60y) = 333768

-21996x + 101520y = 333768

Add the two equations:

(20702x - 25404y) + (-21996x + 101520y) = 307636 + 333768

-1294x + 76116y = 641404

Now we have two equations:

-1294x + 76116y = 641404

20702x - 25404y = 307636

Multiply the first equation by 16:

16(-1294x + 76116y) = 16(641404)

-20704x + 1217856y = 10262544

Add the two equations:

(-20704x + 1217856y) + (20702x - 25404y) = 10262544 + 307636

-2x + 1192452y = 10570180

Now we have two equations:

-2x + 1192452y = 10570180

-2x + 596226y = 5285090

Subtract the second equation from the first equation:

(-2x + 1192452y) - (-2x + 596226y) = 10570180 - 5285090

596226y - 596226y = 5285090

0 = 5285090

This equation is not possible, which means there is no solution to the system of equations. The system is inconsistent or contradictory.

User Ken Russell
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