By definition, the number
is the ratio between the circumference and the diameter:

This implies that

And so your circumference is 
#15(A)
First Bike
$380 - $190 ($380 * 0.50) = $190
2nd Bike
$380 - $114 ( $380 * 0.30) = $266
$266 - $53.20 ($266 * 0.20) = $212.80
#15 (B)
Eliza should buy the first bike because it is cheaper. $190 < $212.80
#16
$57 + $28.50 ($57 * .50) = $85.50
Answer:
Solve the equation for y by finding a, b, and c
of the quadratic then applying the quadratic formula.
Exact Form:
y = 3,−9/2
Decimal Form:
y = 3,−4.5
Mixed Number Form:
y = 3,− 4 1/2
Step-by-step explanation:
branliest pls