y = 0.35x
Step-by-step explanation:
Janet ⇒ 3 postcards ⇒ $1.05
Cost of postcard: 1.05/3 = $0.35
Rosi ⇒ 5 postcards ⇒ $1.75
Cost of postcard: 1.75/5 = $0.35
Tanya ⇒ 8 postcards ⇒ $2.80
Cost of postcard: $2.80/8 = $0.35
We see in all 3 cases cost of postcard is same, the cost and numbers are proportional and the relationship is:
y = 0.35x
