Sums, differences and products

This task is about basic facts.
 
Joey has forgotten some of his basic fact tables. Help Joey by filling in two numbers in the spaces to make each row true.
The first one has been done for you by writing in the numbers 6 and 7.  

Question 1Change answer

  Numbers Sum Difference Product
a) 6   and   7 13 1 42
b)    and    7 1 12
c)    and    9 1 20
d)    and    9 3 18
e)    and    12 0 36
f)    and    12 8 20
g)    and    13 3 40
h)    and    11 5 24