Answer:
$79.
Step-by-step explanation:
Mandy bought 9 plants (3 plants for 3 friends) = $4 x 9 friends = $36.
Mandy bought 6 bags of soil = $8 x 6 = $48.
Adding both together = $48 + $36 = $84
But she saved $5 off her total purchase, so = $84 - $5 = $79.