Well theoretically speaking you could but that would take a long time and 15 and 30 have a common factor of 5 and 15. So I think for this one you can't since there are two common factors.
<span />
Answer:
s=8
Step-by-step explanation:
I'll do 22 for you. 22, 24, 26, 28, and 30, are very similar to each other.
PROPORTIONS:
Draw it out.
5/7 = either c/6, or b/5.
I'll do c/6
5/7 = c/6
solve for c
7c=30
c=30/7
now do the same thing to the remaining side, b.
there!