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7 votes
7 votes
4y+3z=19
-x+z=27
x-3y=-19

Solve the system of equations

User Hanego
by
2.6k points

2 Answers

12 votes
12 votes

Answer:

x = -262/13, y = -5/13, z = 89/13

Explanation:

Solve the following system:

{3 z + 4 y = 19 | (equation 1)

z - x = 27 | (equation 2)

-3 y + x = -19 | (equation 3)

Swap equation 1 with equation 2:

{-x + 0 y + z = 27 | (equation 1)

0 x + 4 y + 3 z = 19 | (equation 2)

x - 3 y + 0 z = -19 | (equation 3)

Add equation 1 to equation 3:

{-x + 0 y + z = 27 | (equation 1)

0 x + 4 y + 3 z = 19 | (equation 2)

0 x - 3 y + z = 8 | (equation 3)

Add 3/4 × (equation 2) to equation 3:

{-x + 0 y + z = 27 | (equation 1)

0 x + 4 y + 3 z = 19 | (equation 2)

0 x + 0 y + (13 z)/4 = 89/4 | (equation 3)

Multiply equation 3 by 4:

{-x + 0 y + z = 27 | (equation 1)

0 x + 4 y + 3 z = 19 | (equation 2)

0 x + 0 y + 13 z = 89 | (equation 3)

Divide equation 3 by 13:

{-x + 0 y + z = 27 | (equation 1)

0 x + 4 y + 3 z = 19 | (equation 2)

0 x + 0 y + z = 89/13 | (equation 3)

Subtract 3 × (equation 3) from equation 2:

{-x + 0 y + z = 27 | (equation 1)

0 x + 4 y + 0 z = -20/13 | (equation 2)

0 x + 0 y + z = 89/13 | (equation 3)

Divide equation 2 by 4:

{-x + 0 y + z = 27 | (equation 1)

0 x + y + 0 z = -5/13 | (equation 2)

0 x + 0 y + z = 89/13 | (equation 3)

Subtract equation 3 from equation 1:

{-x + 0 y + 0 z = 262/13 | (equation 1)

0 x + y + 0 z = -5/13 | (equation 2)

0 x + 0 y + z = 89/13 | (equation 3)

Multiply equation 1 by -1:

{x + 0 y + 0 z = -262/13 | (equation 1)

0 x + y + 0 z = -5/13 | (equation 2)

0 x + 0 y + z = 89/13 | (equation 3)

Collect results:

Answer: {x = -262/13, y = -5/13, z = 89/13

User Arithran
by
2.6k points
20 votes
20 votes
4
y
+
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=
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User Antoox
by
2.5k points