How do you factorise 3a - 15? Please include an explaination on what steps you take to work it out. Thanks
You can write 15 as 3*5 so both 3a and 15 have the number 3 in common. This can be factored out
3a - 15 → 3a - 3*5 → 3(a - 5)
That's as far as it goes.
