Two sides of a triangle have the following measures. Find the range of possible measures for the third side.
15, 23

Which is the equation of an ellipse with directrices at x = ±4 and foci at (2, 0) and (−2, 0)?

Precalculus question, image attached.

Julie buys 2kg of apples and 7kg of pears ? 12.70. the pears cost ? 1.30 per kilogram what is the price per kilogram of the apples? show your working out