Soal turunan F(x)=(7x+5)Cos X Plis bantuin dong !!

f(x)=(7x+5)cos x
misal:
7x+5=u
u'=7
cos x=v
v'=-sin x
f(x)=u.v
f'(x)=u'.v+v'.u
=7(cos x)+(-sin x)(7x+5)
=7 cos x - (7x+5) sin x