Question

Write an algebraic equation for the following: The difference between the number a and three times b is equal to twelve.
a − 3b = 12
3b − a = 12
3(a − b) = 12
3a − b = 12

Answer 1

So what does the statement "the difference of a and b " look like? Do you know? Look like as in I mean symbolically

Answer 2

The difference of u and v is written as u-v.
I switched to u and v since your problem uses a and b

Answer 3

How do you represent 3 times b?