a*b=a-b+a-b. How much larger is 12*3 than 10*5?

a*b = a - b + a - b

12*3 = 12 - 3 + 12 - 3 =  ?

10*5 = 10 - 4 + 10 - 5 = ??

Then subtract ?? from ?

a*b=a-b+a-b. How much larger is 12*3 than 10*5?

Using the relation as defined, we have

12 - 3 + 12 - 3  = 18    and    10 - 5 + 10 - 5  = 10

So 12*3 is "greater" than 10*5  by 8......