How many solutions does the system of equations below have?3x+y+3z=−52x−3y−3z=163x+2y+z=−17Choices:(A)no solution(B)one solution(C)infinitely many solutions
Q. How many solutions does the system of equations below have?3x+y+3z=−52x−3y−3z=163x+2y+z=−17Choices:(A)no solution(B)one solution(C)infinitely many solutions
Solve System: First, let's try to solve the system using elimination or substitution.
Eliminate z: We can multiply the second equation by 3 and add it to the first equation to eliminate z. (3x+y+3z)+3×(2x−3y−3z)=−5+3×16
Combine Equations: This simplifies to 3x+y+3z+6x−9y−9z=−5+48.
Add Third Equation: Combining like terms, we get 9x−8y−6z=43.
Check Consistency: Now, let's add the third equation to the new equation we just found.(9x−8y−6z)+(3x+2y+z)=43−17
Form Coefficients Matrix: This simplifies to 12x−6y−5z=26.
Calculate Determinant: We can now try to solve for one of the variables, but we notice that we have 3 equations with 3 variables. We need to check if the equations are consistent and independent.
Check Non-Zero Determinant: If we look at the coefficients of the variables in the original equations, we can form a matrix and check its determinant to see if the system has a unique solution.
Unique Solution: The matrix formed by the coefficients is:∣∣3amp;1amp;32amp;−3amp;−33amp;2amp;1∣∣
Unique Solution: The matrix formed by the coefficients is:∣∣3amp;1amp;32amp;−3amp;−33amp;2amp;1∣∣Calculating the determinant of this matrix, if it's non-zero, there is one solution. If it's zero, we have either no solution or infinitely many solutions.
Unique Solution: The matrix formed by the coefficients is:∣∣3amp;1amp;32amp;−3amp;−33amp;2amp;1∣∣Calculating the determinant of this matrix, if it's non-zero, there is one solution. If it's zero, we have either no solution or infinitely many solutions.The determinant is 3(−3)1+1(−3)3+3⋅2⋅2−3(−3)3−1⋅2⋅3−3⋅2⋅1.
Unique Solution: The matrix formed by the coefficients is:∣∣3amp;1amp;32amp;−3amp;−33amp;2amp;1∣∣Calculating the determinant of this matrix, if it's non-zero, there is one solution. If it's zero, we have either no solution or infinitely many solutions.The determinant is 3(−3)1+1(−3)3+3⋅2⋅2−3(−3)3−1⋅2⋅3−3⋅2⋅1.This simplifies to −9+−9+12−(−27)−6−6.
Unique Solution: The matrix formed by the coefficients is:∣∣3amp;1amp;32amp;−3amp;−33amp;2amp;1∣∣Calculating the determinant of this matrix, if it's non-zero, there is one solution. If it's zero, we have either no solution or infinitely many solutions.The determinant is 3(−3)1+1(−3)3+3⋅2⋅2−3(−3)3−1⋅2⋅3−3⋅2⋅1.This simplifies to −9+−9+12−(−27)−6−6.The determinant is −9−9+12+27−6−6, which equals −9.
Unique Solution: The matrix formed by the coefficients is:∣∣3amp;1amp;32amp;−3amp;−33amp;2amp;1∣∣Calculating the determinant of this matrix, if it's non-zero, there is one solution. If it's zero, we have either no solution or infinitely many solutions.The determinant is 3(−3)1+1(−3)3+3⋅2⋅2−3(−3)3−1⋅2⋅3−3⋅2⋅1.This simplifies to −9+−9+12−(−27)−6−6.The determinant is −9−9+12+27−6−6, which equals −9.Since the determinant is non-zero, the system has a unique solution.
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