How many zeros (xintercepts) can a parabola have?

How many zeros (x­intercepts) can a parabola have?
1
Find the equation, in 3 different forms, of the quadratic with zeros at ­5 and 3 and with a y­intercept of ­45.
2
Does the following quadratic open up or down?
y=3(x+4)(8­x)
3
Can a be equal to zero? Explain. 4
5
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Homework: Pg. 186 #6b,7b, 10 and Pg. 192 #4ad, 5, 7, 15 11