Dishwasher detergent is sold in individual packets. The 20 packet box sells for $5.49. The 60 packet box sells for $10.97. The 90 packet box sells for $18.95. Which is the best buy?

60 packets

Step-by-step explanation:

Given that :

Unit cost of 20 packets

$5.49 / 20 =$0.2745

Unit cost of 60 packets :

$10.97 / 60 = $0.1828333

Unit cost of 90 packets :

$18.95 / 90 = $0.2105555

The 60 packets has the least cost per unit, hence it is the best buy.

stops on an even number.

step-by-step explanation:

y = | -2(-2) |     →     y = | 4 |     →     y = 4       ⇒   (-2, 4)

y = | -2(-1) |     →     y = | 2 |     →       y =   2       ⇒   (-1, 2)    

y = | -2(0) |     →     y = | 0 |     →       y = 0         ⇒   (0, 0)

y = | -2(1) |   c →     y = | -2 |     →     y =   2         ⇒   (1, 2)    

y = | -2(2) |     →     y = | - 4 |     →     y =   4         ⇒   (2, 4)