We know the perimeter is the total sum of all sides of the shape, we can use this to form an equation: the perimeter=1st side + 2nd side + 3rd side + 4th side 39a-7=9a+(5a+1)+(17a-6)+4th side.
Collect like terms to get 39a-7=31a-5+4th side
If we move everything but the 4th side over to the left we can solve
C. 8a-2=4th side is the correct answer
Answer:
$150
Step-by-step explanation:
I feel like this is a trick question
The 90% confidence interval is (70 - 4, 70 + 4). The margin of error is 4%.
