system equation will be given by
cost of a Hotel for 4 nights + charge per extra person
let the total cost be = c
let the cost of a hotel for 4 nights = x
and
let the charge per extra person = y
let a be the number of extra persons = 3
so the equation becomes
x + ay = c
For Hotel A
c = 352 + 3(20) =352 + 60 = $412
For Hotel B
c = 220 + 3(35) = 220 + 105 = $325
Hence Hotel B has a lower price than Hotel Aiio