Answer:
1011011
Step-by-step explanation:
The binary multiplication is pretty much like the decimal one, we have just to remember that in the binary system 1+1 = 10.
First, convert 7 and 13 to binary
7 = 111
13 = 1101
now multiply with the same rules as in decimal
1101x
111
--------------
1101+
1101 +
1101
1111
-------------
1011011
The last row of digits are the carry bits.
So 7*13 = 1101*111(binary) = 1011011 (binary)
7 = 00110111
13 = 00110001 00110011
7 x 13 = 91
00110111 x 00110001 00110011 = 00111001 00110001
