Question

Mary bought a smart phone and has $11.43 left. How much did Mary have before she bought the smart phone? Write an equation and solve it by using the information in the table.


A 2-column table with 4 rows. Column 1 is labeled Electronics with entries Mp3 player, computer, tablet, smart phone. Column 2 is labeled Sale Price in dollars with entries 39, 299, 199, 78.

$27.57
$50.43
$66.57
$89.43

Answer 1

Let m be the amount Mary had before buying. From the table the smart phone costs \$78, and she has \$11.43 left, so

m − 78 = 11.43.

Solve: m = 78 + 11.43 = \$89.43.