Solve the following system of linear equations using Cramer's rule: x + 2y + 3z = 1, 3x + 2y + z = 4, x + 3y + 2z = 0
|Mathematics
Solve the following system of linear equations using Cramer's rule: x + 2y + 3z = 1, 3x + 2y + z = 4, x + 3y + 2z = 0
ScanSolve AI Answer
Answer
47
To solve the system of equations using Cramer's Rule:
x+2y+3z=1
3x+2y+z=4
x+3y+2z=0
Step 1: Write the coefficient matrix A and the constant vector B.
A=131223312andB=140
Step 2: Calculate the determinant of the coefficient matrix, D.
D=det(A)=131223312D=12312−23112+33123D=1((2)(2)−(1)(3))−2((3)(2)−(1)(1))+3((3)(3)−(2)(1))D=1(4−3)−2(6−1)+3(9−2)D=1(1)−2(5)+3(7)D=1−10+21=12
Step 3: Calculate Dx by replacing the first column of A with B.
Dx=140223312Dx=12312−24012+34023Dx=1((2)(2)−(1)(3))−2((4)(2)−(1)(0))+3((4)(3)−(2)(0))Dx=1(4−3)−2(8−0)+3(12−0)Dx=1(1)−2(8)+3(12)Dx=1−16+36=21
Step 4: Calculate Dy by replacing the second column of A with B.
Dy=131140312Dy=14012−13112+33140Dy=1((4)(2)−(1)(0))−1((3)(2)−(1)(1))+3((3)(0)−(4)(1))Dy=1(8−0)−1(6−1)+3(0−4)Dy=1(8)−1(5)+3(−4)Dy=8−5−12=−9
Step 5: Calculate Dz by replacing the third column of A with B.
Dz=131223140Dz=12340−23140+13123Dz=1((2)(0)−(4)(3))−2((3)(0)−(4)(1))+1((3)(3)−(2)(1))Dz=1(0−12)−2(0−4)+1(9−2)Dz=1(−12)−2(−4)+1(7)Dz=−12+8+7=3
Step 6: Apply Cramer's Rule to find x,y,z.
x=DDx=1221=47y=DDy=12−9=−43z=DDz=123=41
The solution is:
x = \frac{7{4}}y = -\frac{3{4}}z = \frac{1{4}}
3 done, 2 left today. You're making progress.
Was this helpful?
Need help with your own homework?
Get instant step-by-step solutions to any question. Free to start.
To solve the system of equations using Cramer's Rule: 1) x + 2y + 3z = 1 2) 3x + 2y + z = 4 3) x + 3y + 2z = 0 Step 1: Write the coefficient matrix A and the constant vector B.
Solve the following system of linear equations using Cramer's rule: x + 2y + 3z = 1, 3x + 2y + z = 4, x + 3y + 2z = 0
This mathematics problem involves applying core mathematical principles and formulas. Below you will find a complete step-by-step solution with detailed explanations for each step, helping you understand not just the answer but the method behind it.
ScanSolve AI Answer
To solve the system of equations using Cramer's Rule: 1) x + 2y + 3z = 1 2) 3x + 2y + z = 4 3) x + 3y + 2z = 0 Step 1: Write the coefficient matrix A and the constant vector B. A = 1 & 2 & 3 \\ 3 & 2 & 1 \\ 1 & 3 & 2 and B = 1 \\ 4 \\ 0 Step 2: Calculate the determinant of the coefficient matrix, D. D = (A) = 1 & 2 & 3 \\ 3 & 2 & 1 \\ 1 & 3 & 2 D = 1 2 & 1 \\ 3 & 2 - 2 3 & 1 \\ 1 & 2 + 3 3 & 2 \\ 1 & 3 D = 1((2)(2) - (1)(3)) - 2((3)(2) - (1)(1)) + 3((3)(3) - (2)(1)) D = 1(4 - 3) - 2(6 - 1) + 3(9 - 2) D = 1(1) - 2(5) + 3(7) D = 1 - 10 + 21 = 12 Step 3: Calculate D_x by replacing the first column of A with B. D_x = 1 & 2 & 3 \\ 4 & 2 & 1 \\ 0 & 3 & 2 D_x = 1 2 & 1 \\ 3 & 2 - 2 4 & 1 \\ 0 & 2 + 3 4 & 2 \\ 0 & 3 D_x = 1((2)(2) - (1)(3)) - 2((4)(2) - (1)(0)) + 3((4)(3) - (2)(0)) D_x = 1(4 - 3) - 2(8 - 0) + 3(12 - 0) D_x = 1(1) - 2(8) + 3(12) D_x = 1 - 16 + 36 = 21 Step 4: Calculate D_y by replacing the second column of A with B. D_y = 1 & 1 & 3 \\ 3 & 4 & 1 \\ 1 & 0 & 2 D_y = 1 4 & 1 \\ 0 & 2 - 1 3 & 1 \\ 1 & 2 + 3 3 & 4 \\ 1 & 0 D_y = 1((4)(2) - (1)(0)) - 1((3)(2) - (1)(1)) + 3((3)(0) - (4)(1)) D_y = 1(8 - 0) - 1(6 - 1) + 3(0 - 4) D_y = 1(8) - 1(5) + 3(-4) D_y = 8 - 5 - 12 = -9 Step 5: Calculate D_z by replacing the third column of A with B. D_z = 1 & 2 & 1 \\ 3 & 2 & 4 \\ 1 & 3 & 0 D_z = 1 2 & 4 \\ 3 & 0 - 2 3 & 4 \\ 1 & 0 + 1 3 & 2 \\ 1 & 3 D_z = 1((2)(0) - (4)(3)) - 2((3)(0) - (4)(1)) + 1((3)(3) - (2)(1)) D_z = 1(0 - 12) - 2(0 - 4) + 1(9 - 2) D_z = 1(-12) - 2(-4) + 1(7) D_z = -12 + 8 + 7 = 3 Step 6: Apply Cramer's Rule to find x, y, z. x = (D_x)/(D) = (21)/(12) = (7)/(4) y = (D_y)/(D) = (-9)/(12) = -(3)/(4) z = (D_z)/(D) = (3)/(12) = (1)/(4) The solution is: x = (7)/(4) y = -(3)/(4) z = (1)/(4) 3 done, 2 left today. You're making progress.