Aljabar Linear Contoh
x+2y−z=4 , 2x+y+z=−2 , x+2y+z=2
Langkah 1
Write the system as a matrix.
⎡⎢
⎢⎣12−14211−21212⎤⎥
⎥⎦
Langkah 2
Langkah 2.1
Perform the row operation R2=R2−2R1 to make the entry at 2,1 a 0.
Langkah 2.1.1
Perform the row operation R2=R2−2R1 to make the entry at 2,1 a 0.
⎡⎢
⎢⎣12−142−2⋅11−2⋅21−2⋅−1−2−2⋅41212⎤⎥
⎥⎦
Langkah 2.1.2
Sederhanakan R2.
⎡⎢
⎢⎣12−140−33−101212⎤⎥
⎥⎦
⎡⎢
⎢⎣12−140−33−101212⎤⎥
⎥⎦
Langkah 2.2
Perform the row operation R3=R3−R1 to make the entry at 3,1 a 0.
Langkah 2.2.1
Perform the row operation R3=R3−R1 to make the entry at 3,1 a 0.
⎡⎢
⎢⎣12−140−33−101−12−21+12−4⎤⎥
⎥⎦
Langkah 2.2.2
Sederhanakan R3.
⎡⎢
⎢⎣12−140−33−10002−2⎤⎥
⎥⎦
⎡⎢
⎢⎣12−140−33−10002−2⎤⎥
⎥⎦
Langkah 2.3
Multiply each element of R2 by −13 to make the entry at 2,2 a 1.
Langkah 2.3.1
Multiply each element of R2 by −13 to make the entry at 2,2 a 1.
⎡⎢
⎢⎣12−14−13⋅0−13⋅−3−13⋅3−13⋅−10002−2⎤⎥
⎥⎦
Langkah 2.3.2
Sederhanakan R2.
⎡⎢
⎢⎣12−1401−1103002−2⎤⎥
⎥⎦
⎡⎢
⎢⎣12−1401−1103002−2⎤⎥
⎥⎦
Langkah 2.4
Multiply each element of R3 by 12 to make the entry at 3,3 a 1.
Langkah 2.4.1
Multiply each element of R3 by 12 to make the entry at 3,3 a 1.
⎡⎢
⎢
⎢⎣12−1401−1103020222−22⎤⎥
⎥
⎥⎦
Langkah 2.4.2
Sederhanakan R3.
⎡⎢
⎢⎣12−1401−1103001−1⎤⎥
⎥⎦
⎡⎢
⎢⎣12−1401−1103001−1⎤⎥
⎥⎦
Langkah 2.5
Perform the row operation R2=R2+R3 to make the entry at 2,3 a 0.
Langkah 2.5.1
Perform the row operation R2=R2+R3 to make the entry at 2,3 a 0.
⎡⎢
⎢⎣12−140+01+0−1+1⋅1103−1001−1⎤⎥
⎥⎦
Langkah 2.5.2
Sederhanakan R2.
⎡⎢
⎢⎣12−1401073001−1⎤⎥
⎥⎦
⎡⎢
⎢⎣12−1401073001−1⎤⎥
⎥⎦
Langkah 2.6
Perform the row operation R1=R1+R3 to make the entry at 1,3 a 0.
Langkah 2.6.1
Perform the row operation R1=R1+R3 to make the entry at 1,3 a 0.
⎡⎢
⎢⎣1+02+0−1+1⋅14−101073001−1⎤⎥
⎥⎦
Langkah 2.6.2
Sederhanakan R1.
⎡⎢
⎢⎣120301073001−1⎤⎥
⎥⎦
⎡⎢
⎢⎣120301073001−1⎤⎥
⎥⎦
Langkah 2.7
Perform the row operation R1=R1−2R2 to make the entry at 1,2 a 0.
Langkah 2.7.1
Perform the row operation R1=R1−2R2 to make the entry at 1,2 a 0.
⎡⎢
⎢
⎢
⎢⎣1−2⋅02−2⋅10−2⋅03−2(73)01073001−1⎤⎥
⎥
⎥
⎥⎦
Langkah 2.7.2
Sederhanakan R1.
⎡⎢
⎢
⎢⎣100−5301073001−1⎤⎥
⎥
⎥⎦
⎡⎢
⎢
⎢⎣100−5301073001−1⎤⎥
⎥
⎥⎦
⎡⎢
⎢
⎢⎣100−5301073001−1⎤⎥
⎥
⎥⎦
Langkah 3
Use the result matrix to declare the final solution to the system of equations.
x=−53
y=73
z=−1
Langkah 4
The solution is the set of ordered pairs that make the system true.
(−53,73,−1)