Question 647567
p(a) = a^2 + 3

p(a-1) = (a-1)^2 + 3 =  (a^2 -2a + 1) +3 by foil.

so continuing: p(a-1) = a^2 -2a +4 

Now substitute.

2*(a^2+3) + a^2 -2a +4 

2a^2 + 6 +a^2 - 2a + 4  by distributive property

Now combine like terms

(2a^2 + a^2) - 2a  + (6+4)

3a^2 - 2a + 10

If you have any questions about the steps presented here, email me at my private email: OnlyYourMathTutor@yahoo.com

Otherwise hope this was clear!

-Devin