I need this solved using derivatives please

Acompany is making new soccer uniforms for a team. the company uses 2.5 yards of fabric for each shirt. the company uses 82.5 yards of fabric to make shirts and shorts for 15 players. the equation and solution below represents the situation. 15(2.5+x)=82.5; x=3 what does the solution, x=3, represent?

Although changes result from business transactions, the equality of the fundamental bookkeeping equation must remain. t/f

State if the two triangles are congruent. if they are, state how you know?