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9-53.

f is concave up when f ″ is positive. Where is the given graph positive?

This is asking for the slope of the given graph at x = 5.

This is where f ″ changes sign. Where does the given graph change from negative to positive and vice versa?

f ′ has a minimum where its slope changes from negative to positive.
The slope of f ′ is f ″. So where does f ″ change from negative to positive?