MATH HELP FUNCTIONS

First find  f(4)   =  2(4) - 3 = 5

then find   g (5) = 5 - 4(5) = -15

$f(x)=2x-3 \quad and \quad g(f(x))=5-4x\qquad \qquad \\Find \;\; g(4)\\ f(x)=4\\ 5-4x=4\\ -4x=-1\\ x=0.25\\ g(4)=g(f(0.25))=5-4*0.25 = 1$