[tex]\huge{\boxed{\tt{Solution :}}}[/tex]
Now we solving it :
[tex] \sf{ : \implies{ g(r) = 25 - 3r}} \\ \\ \sf{ : \implies{ g(4) = 25 - 3 \times 4}} \\ \\ \sf{ : \implies{ g(4) = 25 -12 }} \\ \\ : \implies{ \boxed{ \tt{g(4) = 13 }}}[/tex]
[tex]\bf {\therefore{The\:value\:of \:g (4)\:is\:13.}}[/tex]
[tex]\rule {307}{2}[/tex]