f(x) = 3x^2 - 2x.......................... f(a+1)?

Question

f(x) = 3x^2 - 2x.......................... f(a+1)

Answer 1

Hey there!

Here's the answer.

f(x)=3x^2-2x --> Write the problem.
f(a+1)=3(a+1)^2-2(a+1) --> Substitute a+1 for x.
f(a+1)=3(a^2+2a+1)-2(a+1) --> Simplify the above equation. Use FOIL to find (a+1)^2.
f(a+1)=3a^2+6a+3-2a-2 --> Distribute 3 into a^2+2a+1 and distribute -2 into a+1.
f(a+1)=3a^2+6a-2a+3-2 --> Group the a^2 terms together, a terms together and constant terms together.
f(a+1)=3a^2+4a+1 --> Simplify the above equation.

So the answer is f(a+1)=3a^2+4a+1.

Answer 2

f(x) = 3x^2 - 2x

f(a+1) = 3*(a+1)^2 - 2(a+1)
f(a+1) = 3a^2 + 6a + 3 - 2a - 2
f(a+1) = 3a^2 + 4a + 1