In this case, since one equation is in the form of x=, substitution would be best for this problem. Simply plug in 4y + 8 in place of x in the second equation, solve for y, then plug that value into the first equation to find x.
"a ∝ b" means "a is proportional to b", which in turn means there is some constant k such that
a = kb
We're given that a = 18 and b = 3, so that
18 = 3k ⇒ k = 6
Then when b = 5, we would have
a = 6 × 5 = 30
18 line segments also for faster and better u can 6 times 3 since there is already three in a triangle.
