simply divide f(x) by g(x) ,,then write it in the form
f(x)=g(x)×q(x)+r(x)
where r is the remainder and q(x) is the quotient
on dividing we will get
q(x)=(x+3)
r(x)=0
this shows that g(x) is the factor of f(x)
now we can write
f(x)=(x+3)(x+5)+0
this will be the required answer
hope it helps you
