Which of the purchases would be the least expensive?

purchase
amount of sale
sales tax rate
a
$150
5%
b
$145
7%
c
$140
8%
d
$135
9%

Purchase D would be the least expensive.

Step-by-step explanation:

To find which of the purchase would be the least expensive, we have to add all the purchase amount to the sale tax.

Purchase A.  Amount of sale = 150

Sales tax rate = 5%

Total = 150 + (5% of 150)

= 150 + (0.05 × 150)

= 150 + 7.5 = $157.50

Purchase B. Amount of sale = $145.00

Sales tax rate = 7%

Total = 145 + (7% of 145)

145 + (0.07 × 145)

145 + 10.15 = $155.15

Purchase C. Amount of sale = $140.00

Sales tax rate = 8%

Total = 140 + (8% of 140)

= 140 (0.08 × 140)

= 140 + 11.20 = $151.20

Purchase D.  Amount of sale = $135.00

Sales tax rate = 9%

Total = 135 + (9% of 135)

135 + (0.09 × 135)

135 + 12.15 = $147.15

Purchase D would be the least expensive.

because they could drop even lower..