Ensembles finis Exemples
x+3y-z=4x+3y−z=4 , 3y-z=03y−z=0 , x-y+5z=0x−y+5z=0
Étape 1
Write the system as a matrix.
[13-1403-101-150]⎡⎢
⎢⎣13−1403−101−150⎤⎥
⎥⎦
Étape 2
Étape 2.1
Perform the row operation R3=R3-R1R3=R3−R1 to make the entry at 3,13,1 a 00.
Étape 2.1.1
Perform the row operation R3=R3-R1R3=R3−R1 to make the entry at 3,13,1 a 00.
[13-1403-101-1-1-35+10-4]⎡⎢
⎢⎣13−1403−101−1−1−35+10−4⎤⎥
⎥⎦
Étape 2.1.2
Simplifiez R3R3.
[13-1403-100-46-4]⎡⎢
⎢⎣13−1403−100−46−4⎤⎥
⎥⎦
[13-1403-100-46-4]⎡⎢
⎢⎣13−1403−100−46−4⎤⎥
⎥⎦
Étape 2.2
Multiply each element of R2R2 by 1313 to make the entry at 2,22,2 a 11.
Étape 2.2.1
Multiply each element of R2R2 by 1313 to make the entry at 2,22,2 a 11.
[13-140333-13030-46-4]⎡⎢
⎢
⎢⎣13−140333−13030−46−4⎤⎥
⎥
⎥⎦
Étape 2.2.2
Simplifiez R2R2.
[13-1401-1300-46-4]⎡⎢
⎢⎣13−1401−1300−46−4⎤⎥
⎥⎦
[13-1401-1300-46-4]⎡⎢
⎢⎣13−1401−1300−46−4⎤⎥
⎥⎦
Étape 2.3
Perform the row operation R3=R3+4R2R3=R3+4R2 to make the entry at 3,23,2 a 00.
Étape 2.3.1
Perform the row operation R3=R3+4R2R3=R3+4R2 to make the entry at 3,23,2 a 00.
[13-1401-1300+4⋅0-4+4⋅16+4(-13)-4+4⋅0]⎡⎢
⎢
⎢
⎢⎣13−1401−1300+4⋅0−4+4⋅16+4(−13)−4+4⋅0⎤⎥
⎥
⎥
⎥⎦
Étape 2.3.2
Simplifiez R3R3.
[13-1401-13000143-4]⎡⎢
⎢
⎢⎣13−1401−13000143−4⎤⎥
⎥
⎥⎦
[13-1401-13000143-4]⎡⎢
⎢
⎢⎣13−1401−13000143−4⎤⎥
⎥
⎥⎦
Étape 2.4
Multiply each element of R3R3 by 314314 to make the entry at 3,33,3 a 11.
Étape 2.4.1
Multiply each element of R3R3 by 314314 to make the entry at 3,33,3 a 11.
[13-1401-130314⋅0314⋅0314⋅143314⋅-4]⎡⎢
⎢
⎢⎣13−1401−130314⋅0314⋅0314⋅143314⋅−4⎤⎥
⎥
⎥⎦
Étape 2.4.2
Simplifiez R3R3.
[13-1401-130001-67]⎡⎢
⎢
⎢⎣13−1401−130001−67⎤⎥
⎥
⎥⎦
[13-1401-130001-67]⎡⎢
⎢
⎢⎣13−1401−130001−67⎤⎥
⎥
⎥⎦
Étape 2.5
Perform the row operation R2=R2+13R3R2=R2+13R3 to make the entry at 2,32,3 a 00.
Étape 2.5.1
Perform the row operation R2=R2+13R3R2=R2+13R3 to make the entry at 2,32,3 a 00.
[13-140+13⋅01+13⋅0-13+13⋅10+13(-67)001-67]⎡⎢
⎢
⎢
⎢⎣13−140+13⋅01+13⋅0−13+13⋅10+13(−67)001−67⎤⎥
⎥
⎥
⎥⎦
Étape 2.5.2
Simplifiez R2R2.
[13-14010-27001-67]⎡⎢
⎢
⎢⎣13−14010−27001−67⎤⎥
⎥
⎥⎦
[13-14010-27001-67]⎡⎢
⎢
⎢⎣13−14010−27001−67⎤⎥
⎥
⎥⎦
Étape 2.6
Perform the row operation R1=R1+R3R1=R1+R3 to make the entry at 1,31,3 a 00.
Étape 2.6.1
Perform the row operation R1=R1+R3R1=R1+R3 to make the entry at 1,31,3 a 00.
[1+03+0-1+1⋅14-67010-27001-67]⎡⎢
⎢
⎢
⎢⎣1+03+0−1+1⋅14−67010−27001−67⎤⎥
⎥
⎥
⎥⎦
Étape 2.6.2
Simplifiez R1.
[130227010-27001-67]
[130227010-27001-67]
Étape 2.7
Perform the row operation R1=R1-3R2 to make the entry at 1,2 a 0.
Étape 2.7.1
Perform the row operation R1=R1-3R2 to make the entry at 1,2 a 0.
[1-3⋅03-3⋅10-3⋅0227-3(-27)010-27001-67]
Étape 2.7.2
Simplifiez R1.
[1004010-27001-67]
[1004010-27001-67]
[1004010-27001-67]
Étape 3
Use the result matrix to declare the final solution to the system of equations.
x=4
y=-27
z=-67
Étape 4
The solution is the set of ordered pairs that make the system true.
(4,-27,-67)