we have that
a01
and
20cba
step 1
convert to decimal values
a01-----> [10*16²+0*16+1*16^0]---> [2560+1]------> 2561
20cba--> [ 2*16^4+0*16^3+12*16^2+11*16^1+10*16^0]
=[131072+3072+176+10]
=134330
step 2
find the sum
2561+134330-----> 136891
step 3
find the product
2561*134330----> 344019130
step 4
convert to hexadecimal------> using a Hexadecimal calculator
the sum
136891---------> 216BB
the product
344019130-----> 148150BA
