Question

The Perez family is researching the cost of keeping their dog at a kennel during an upcoming vacation. The local kennel allows “Silver” families to pay a rate of $36 per day. For a fee, families can buy a “Gold” membership and will be allowed to board their dogs at a discounted rate as shown in the table.

Total Cost, Including Membership Fee, to Board a Dog
Type of membership
1 Day
2 Days
7 Days
Silver
$36
$72
$252
Gold
$70
$90
$190

What is the cost of a Gold membership?
$20
$34
$50
$70

Answer 1

if we interpret the first two points in the gold table as

day 1 = $70
day 2 = $90

we can write an equation in the form

cost = amount per day * number of days + fee

Answer 2

we can re-write the two values as

(1,70) and (2,90) and use the slope equation and the point-slope formula to write the equation