Tolong ya nomor 5,6,7 sama caranya yaaa plis

5.)diketahui:
rumus fungsi f(x)=px+q
jika f(3)=9 dan f(-6)=3
ditanya:
rumus fungsi f(x)=...
jawab:
f(x)=px+q
f(3)=p.9+q
f(3)=9p+q
9=9p+q
9p+q=9....1

f(x)=px+q
f(-6)=p.-6+q
f(-6)=-6p+q
3=-6p+q
-6p+q=3....2

9p+q=3....1
-
-6p+q=3...2

9p-6p+q-(+q)=9-3
3p+b-b=6
3p+0=6
3p=6
p=6/3
p=2

9p+q=9......1
9.2+q=9
18+q=9
q=9/18
q=-9/3
=3

f(x)=px+q
f(x)=-2/3x+-7