Factorise 3a-27

since 27 = 3*9,

3a-27 = 3a-3*9 = 3(a-9)

To factorize the expression 3a - 27, we can start by noticing that both terms have a common factor of 3. We can factor out the 3, which leaves us with:

3(a - 9)

So the factorized form of 3a - 27 is 3(a - 9).

To arrive at this answer, we identified that both terms have a factor of 3, and therefore, we extracted that common factor. The remaining expression inside the parentheses can't be simplified further, so we left it as (a - 9).