a. 2 13 x 5 14 = 73 x 214 = 7x213x4 = 14712
b. 3 25 x 2 17 = 175 x 157 = 17x515x7 = 85105
c. 8 16 : 2 12 = 496 : 52 = 49x26x5 = 9830