Erin is buying produce at a store. She buys c cucumbers at $0.69 each and a apples at $0.89 each. What does the expression 0.69c + 0.89a represent? The expression represents the
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The length pf a rectangle is given by 2t +3 and its height is square root t, where t is time in seconds and the dimensions are in centimeters. find the rate of the change of the area with respect to time. a'(t)=