Write the Word or Phrase That Best Completes Each Statement $(x, 0)$

Essay

Write the word or phrase that best completes each statement or answers thequestion.
-You are planning to close off a corner of the first quadrant with a line segment 15 units long running from $(x, 0)$ to $(0, y)$ . Show that the area of the triangle enclosed by the segment is largest when $\mathrm{x}=\mathrm{y}$ .