Math Problem: Tammy figured her math exam would be difficult unless she put in at
least 15 hours of study time to prepare. She studied 2½ hours on
Monday, 3 hours on Tuesday, 4¾ hours on Wednesday, and 4 ½
hours on Thursday. Did she study at least 15 hours? Explain.

She put 14 hours and 45 minutes into studying.

Step-by-step explanation:  2 1/2 hours plus 4 1/2 hours is 7 hours. Plus 3 is 10 hours. Plus 4 3/4 is 14 3/4 hours. 14 3/4 hours is = to 14 hours 45 minutes studying.

if the eqn of the parabola is f(x) = (x-4)(x+2), we need to mult. this out to find the coordinates of the vertex.

then f(x) = x^2 + 2x - 4x - 8, and f(x) = x^2 - 2x - 8.

one way in which you can find the vertex is to calculate x = -b / (2a).   here, that comes to

        )

x = = 1.   f(1) = 1^2 - 2(1) - 8 = - 9.   vertex is at (1, -9).

        2(1) 

find another point on the curve:   let x=0, for which y=-8.   then (0, -8) is on the curve.   plot the vertex and this point and draw a smooth parabola thru both.

hope this

lockers 1, 4, 9, 16, 25, 40, and 49 are open

i ran through it by the other answer is wrong