How can i factor 27+12

Firstly look for the highest number which goes into both of them:

1 goes into both of them
3 goes into both of them and is the highest so we use this one.

Next write a 3 outside a set of brackets:


Then, the point of these brackets is that you times everything inside them by 3 so in order to get the numbers inside, you divide both by 3.




So now put these back into the brackets and you're done:



Try to factorise  now to make sure you understand.

Where’s the