(15 - 6) - 3 = 15 - (6 - 3). is julie's wrote equation sense or nonsense? do you think the associative property works for subtra
1 answer:
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9514 1404 393
Answer:
3.61 seconds
Step-by-step explanation:
The bird starts 50 feet in the air, so will come down to a height of 40 feet after 3.61 seconds.
We want to solve h = 40.
40 = -16t^2 +55t +50
16t^2 -55t -10 = 0
t = (55 +√(55^2 -4(16)(-10)))/(2(16)) = (55 + √3665)/32 ≈ 3.61060
The bird will be 40 ft above the ground the first time after about 3.61 seconds.
