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An object is thrown upward out of a building window. The equation h=-16t²+40t+24 models the height in feet, h, of the object above the ground t seconds after it is thrown. How long does it take for the object to hit the ground?

Respuesta :

sqdancefan

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Answer:

  3 seconds

Step-by-step explanation:

We want to find t when h=0.

  0 = 2t² -5t -3 . . . . . . . divide by -8

  0 = (2t +1)(t -3) . . . . . . factor

The values of t that satisfy this equation are the values that make the factors zero: t = -1/2, t = 3. The positive value is the one of interest.

It takes 3 seconds for the object to hit the ground.

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