Question

If f(x) = 2x^2 + 2, find f(5)

A) 102
B) 52
C) 22
D) -1.5

I got C but I want to make sure it's right because I'm not sure. This is how I solved it.
F(x)2x^2+2
F(5)=2(5)^2+2
F(5)=20+2
F(5)= 22

Answer 1

Well, following the order of PEMDAS, I got choice B. 52

For instance, when you plug in 5 for x, you get F(5)=2(5)^2+2.

Moreover, following PEMDAS, you're supposed to solve what's inside the parenthesis, but since there is no operation going on inside the parenthesis, then you simple move on to the exponent.

In this case, you square the number 5, which gives you F(5)=2(25)+2

After that, you Multiply (letter M in PEMDAS). This results in F(5)=50+2.

Finally, you add them, which results in F=52.

By the way, I noticed a mistake in your work. When multiplying 2 by 5, the answer is 10, not 20.

Anyway, hope this helped! :-)