Find the value of c such that each expression is a perfect-square trinomial.
p^2-30p+c
k^2-5k+c

For ax^2+bx+c
when a=1
take 1/2 of b and square it
that is what c should be ideally

p^2-30p=c
-30/2=-15
(-15)^2=225
c=225
(p-15)^2 is factored form

k^2-5k+c
-5/2
(-5/2)^2=25/4
c=25/4
factored form is (x-5/2)^2

6(2x + 5y)6 (2x) = 12x6 (5y) = 30y12x + 30y