Question 18 (5 points) 7 -3 5 7 3 If A = 5 2 1 and 3 = -3 7 9 , find BA. -1 2 -4 2 5 2 O 38 54 -21 22 11 -25 23 25 -15 O 35 50 -18 10 -22 27 30 -4 O 37 55 -20 23 11 -20 25 28 -9 Not possible Question 19 (5 points) Choose the phrase that best describes the matrix. -1 -3 9 -9 -1 -1 -3 OOOO coefficient matrix augmented matrix in row-echelon form augmented matrix none of the above Question 20 (5 points) -5 -5 3 Find the determinant of I = 5 -3 2 3 1 2 O -102 102 C 88 -22Question 17 (5 points) Graph the region corresponding to the solution of the system of constraints. Ax, v) = 3+x *20 8x + 12v