Answer:
Step-by-step explanation:
Each equation is in vertex form, so you can easily determine the number of real roots. The leading coefficient tells you whether the parabola opens upward (positive) or downward (negative).
y = a(x -h)^2 +k
has leading coefficient "a" and vertex (h, k).
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f(x) = 1/3(x +5)^2 +7
vertex: (-5, 7), opens downward
The vertex is above the x-axis, so there are two real roots.
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f(x) = -5(x -3)^2
vertex: (3, 0), opens downward
The vertex is on the x-axis, so there is one real root.
