Answer
$f(-3)=22$.
$f(2a)=4a^2-6a+4$.
Work Step by Step
The given function is $f(x)=x^2-3x+4$
To find $f(-3)$, replace $x$ with $-3$.
$\Rightarrow f(-3)=(-3)^2-3(-3)+4$
Clear the parentheses.
$\Rightarrow f(-3)=9+9+4$
Add like terms.
$\Rightarrow f(-3)=22$.
To find $f(2a)$, replace $x$ with $2a$.
$\Rightarrow f(2a)=(2a)^2-3(2a)+4$
Clear the parentheses.
$\Rightarrow f(2a)=4a^2-6a+4$.
