[tex]2)~f,~g:\mathbb{R}\rightarrow \mathbb{R},~f(x)=2x-1,~g(x)=-x^2+x\\\\a=f(g(2))-g(f(3))\\\\g(x)=-x^2+x\Rightarrow g(2)=-2^2+2=-4+2=-2\\\\f(x)=2x-1\Rightarrow f(3)=2\cdot3-1=6-1=5\\\\f(g(2))=2\cdot(-2)-1=-4-1=-5\\\\g(f(3))=-5^2+5=-25+5=-20\\\\a=f(g(2))-g(f(3))=-5-(-20)=-5+20=15~~~~~~~~~~~~\boxed{a=15}[/tex]
