Solve the system of equations below.
y=4x
x+y=5

Agreeting card company can produce a box of cards for $7.50. if the initial investment by the company was $50,000, how many boxes of cards must be produced before the average cost per box falls to $10.50?

What is the difference between regular convex and concave polygons

How much dextrose 70% must be mixed with dextrose 5% to prepare 1,000 ml of dextrose 20%?