More applications using systems

Question

A local print shop recently charged 1.9¢ per sheet of​ paper, but 2.5¢ per sheet for paper made of recycled fibers.​ Darren's bill for 190 sheets of paper was $4.45. How many sheets of each type were​ used?

Answer 1

1.9x + 2.5y = 445 cents = $4.45

x+y = 190

solve by substitution elimination, matrix algebra or graphing

x=50 regular sheets of paper

y= 140 sheets of recycled fibers

1.9(50) + 2.5(140) = 95 + 350 = 445

easiest quickest method is use a graphing calculator such as Desmos online

and find the intersection point of the two equations' graphs = (50, 140)