Answer:
225
Step-by-step explanation:
in (a+b)^2, it becomes a^2+2ab+b^2. A in this case would be "K" and b in this case would be 15. K^2+2(K)(15)+(15)^2. That equals k^2+30k+225. The last part is 225.
My trick to do this quickly is you get the "2ab" part. You divide the coefficient by 2 and then square it. For example, the coefficient in 30K is 30. 30/2 is 15. 15^is 225.
