Answer: a = -15
Step-by-step explanation:
3a + b = 9
b=54
3a + 54 = 9
3a = 9-54
3a= -45
<h3>

</h3>
- x + = -
<h2>a= -15</h2>
$78.17 rounds to $78
15% of $78 = $11.70 which rounds to $12
The far left of the chart is the minimum(low) value of the box plot.
Answered by Gauthmath must click thanks and mark brainliest