MATH 2160 (Dr. Ngal) Elementary Linear Algebra Spring 2023 Final Exam May 4, 2023 NAME SCORE /70 /100 INSTRUCTIONS: 1. Show ALL your work in the space provided. 2. Use the indicated method(s) for each problem; other methods may receive NO credit. 3. Calculators CANNOT be used. 4. Circle your answers. 5. This exam covers Sections 1.1-5.3. 1. (a) (5 pts) Use Gauss-Jordan elimination or Gaussian elimination to solve the following system of equations. Other methods receive NO credit. Clearly indicate each ERO used. x + 2y + 3z =9 4x + 5y + 63 = 24 21 + 7y + 12z = 40 (b) (5 pts) Use Cramer's rule to solve for the unknown z in the following system of equations. Other methods receive NO credit. -z=1 2r + 4y - z=1 -r +8y+3z =2