Answer:
y = 0.35x
Step-by-step explanation:
Jane:
Cost of 3 postcards= $1.05
Cost of 1 post card = 1.05 ÷ 3
= $ 0.35
Rosi:
Cost of 5 postcards= $1.75
Cost of 1 post card = 1.75 ÷ 5
= $ 0.35
Tanya:
Cost of 8 postcards= $2.80
Cost of 1 post card = 2.80 ÷ 8
= $ 0.35
As unit rate is same, Cost and number of postcards are in proportion.
Cost of cards = 0.35 * number of cards
y = 0.35*x
y = 0.35x
