Answer :
Given the function:
[tex]f(x)=5x^2-7(4x+3)[/tex]we can find f(3) by making x = 3 and solving for the term f. In this case, we have the following:
[tex]\begin{gathered} f(3)=5(3)^2-7(4(3)+3) \\ =5(9)-7(12+3)=45-7(15)=45-105=-60 \\ \Rightarrow f(3)=-60 \end{gathered}[/tex]therefore, f(3) = -60