Select the correct answer. solve this system of equations using the inverse of a matrix. -1 + y = 8 4x + 3y = 12 1 – 7y + z = 15 [hint: ax = b and x = b4-1; a. b. = 4, y = 68 and 2 = 5.39 r = 68. y = 5.39 and 2 = 4 r = -1.76 y = 6.24 and 2 = 60.76 d. = 6.24, y = –1.76 and 2 = 60.76 r = 72 y = -4 and 2 = 12.78 e.