Bytelearn - cat image with glassesAI tutor

Welcome to Bytelearn!

Let’s check out your problem:

How many solutions does the system of equations below have?\newline3x+y+3z=53x + y + 3z = -5\newline2x3y3z=162x - 3y - 3z = 16\newline3x+2y+z=173x + 2y + z = -17\newlineChoices:\newline(A)no solution\newline(B)one solution\newline(C)infinitely many solutions

Full solution

Q. How many solutions does the system of equations below have?\newline3x+y+3z=53x + y + 3z = -5\newline2x3y3z=162x - 3y - 3z = 16\newline3x+2y+z=173x + 2y + z = -17\newlineChoices:\newline(A)no solution\newline(B)one solution\newline(C)infinitely many solutions
  1. Solve System: First, let's try to solve the system using elimination or substitution.
  2. Eliminate z: We can multiply the second equation by 33 and add it to the first equation to eliminate zz.
    (3x+y+3z)+3×(2x3y3z)=5+3×16(3x + y + 3z) + 3\times(2x - 3y - 3z) = -5 + 3\times16
  3. Combine Equations: This simplifies to 3x+y+3z+6x9y9z=5+483x + y + 3z + 6x - 9y - 9z = -5 + 48.
  4. Add Third Equation: Combining like terms, we get 9x8y6z=439x - 8y - 6z = 43.
  5. Check Consistency: Now, let's add the third equation to the new equation we just found.\newline(9x8y6z)+(3x+2y+z)=4317(9x - 8y - 6z) + (3x + 2y + z) = 43 - 17
  6. Form Coefficients Matrix: This simplifies to 12x6y5z=2612x - 6y - 5z = 26.
  7. Calculate Determinant: We can now try to solve for one of the variables, but we notice that we have 33 equations with 33 variables. We need to check if the equations are consistent and independent.
  8. 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.
  9. Unique Solution: The matrix formed by the coefficients is:\newline3amp;1amp;3 2amp;3amp;3 3amp;2amp;1\begin{vmatrix} 3 & 1 & 3 \ 2 & -3 & -3 \ 3 & 2 & 1 \end{vmatrix}
  10. Unique Solution: The matrix formed by the coefficients is:\newline3amp;1amp;3 2amp;3amp;3 3amp;2amp;1\begin{vmatrix} 3 & 1 & 3 \ 2 & -3 & -3 \ 3 & 2 & 1 \end{vmatrix}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.
  11. Unique Solution: The matrix formed by the coefficients is:\newline3amp;1amp;3 2amp;3amp;3 3amp;2amp;1\begin{vmatrix} 3 & 1 & 3 \ 2 & -3 & -3 \ 3 & 2 & 1 \end{vmatrix}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+3223(3)31233213(-3)1 + 1(-3)3 + 3\cdot2\cdot2 - 3(-3)3 - 1\cdot2\cdot3 - 3\cdot2\cdot1.
  12. Unique Solution: The matrix formed by the coefficients is:\newline3amp;1amp;3 2amp;3amp;3 3amp;2amp;1\begin{vmatrix} 3 & 1 & 3 \ 2 & -3 & -3 \ 3 & 2 & 1 \end{vmatrix}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+3223(3)31233213(-3)1 + 1(-3)3 + 3\cdot2\cdot2 - 3(-3)3 - 1\cdot2\cdot3 - 3\cdot2\cdot1.This simplifies to 9+9+12(27)66-9 + -9 + 12 - (-27) - 6 - 6.
  13. Unique Solution: The matrix formed by the coefficients is:\newline3amp;1amp;3 2amp;3amp;3 3amp;2amp;1\begin{vmatrix} 3 & 1 & 3 \ 2 & -3 & -3 \ 3 & 2 & 1 \end{vmatrix}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+3223(3)31233213(-3)1 + 1(-3)3 + 3\cdot2\cdot2 - 3(-3)3 - 1\cdot2\cdot3 - 3\cdot2\cdot1.This simplifies to 9+9+12(27)66-9 + -9 + 12 - (-27) - 6 - 6.The determinant is 99+12+2766-9 - 9 + 12 + 27 - 6 - 6, which equals 9-9.
  14. Unique Solution: The matrix formed by the coefficients is:\newline3amp;1amp;3 2amp;3amp;3 3amp;2amp;1\begin{vmatrix} 3 & 1 & 3 \ 2 & -3 & -3 \ 3 & 2 & 1 \end{vmatrix}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+3223(3)31233213(-3)1 + 1(-3)3 + 3\cdot2\cdot2 - 3(-3)3 - 1\cdot2\cdot3 - 3\cdot2\cdot1.This simplifies to 9+9+12(27)66-9 + -9 + 12 - (-27) - 6 - 6.The determinant is 99+12+2766-9 - 9 + 12 + 27 - 6 - 6, which equals 9-9.Since the determinant is non-zero, the system has a unique solution.

More problems from Determine the number of solutions to a system of equations in three variables