7.
A. [tex]y=\frac{1}{3}x^2, y=-9x^2, y=-\frac{1}{2}x^2[/tex]
B. [tex]y=-\frac{1}{2}x^2, y=\frac{1}{3}x^2, y=-9x^2[/tex]
C. [tex]y=-9x^2, y=\frac{1}{3}x^2, y=-\frac{1}{2}x^2[/tex]
D. [tex]y=\frac{1}{3}x^2, y=-\frac{1}{2}x^2, y=-9x^2[/tex]
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