## College Algebra 7th Edition

a) $f(f(x))=4x-9$ b) $g(g(x))=-x^4+8x^2-12$
We find the composite functions as follows: a) $f(f(x))=f(2x-3)=2(2x-3)-3=4x-6-3=4x-9$ b) $g(g(x))=g(4-x^2)=4-(4-x^2)^2=4-(16-8x^2+x^4)=-x^4+8x^2-12$