You have to find the gcf of 9 and 15 which is 3 .So then next you know that you have to use 3 so u have to think what 3 times ? gives you 9 which is 3 and you have to think what 3 times ?gives you 15 which is 5.And now u write 3 then a parthness and a 3 and the addition sign which is from the question and lastly 5 which gives you 3 (3 +5)
Hope this help,please give Brainliest if it does.thanks! :)
