Simplify and then evaluate the equation when A=2 and b=4

we have the equation
[tex]b^2+3(b-b^2)-2a[/tex]Remove the parenthesis and apply the distributive property
[tex]b^2+3b-3b^2-2a[/tex]Combine like terms
[tex]-2b^2+3b-2a[/tex]For a=2 and b=4
substitute
[tex]\begin{gathered} -2(4)^2+3(4)-2(2) \\ -32+12-4 \\ -24 \end{gathered}[/tex]