Acash register contains $20 bills and $50 bills with a total value of $810. if there are 21 bills total, then how many of each does the register contain?

If 1/√5+1/√5+1=p+q√r , find the values of p, q and r

Your company will replace the asphalt roofs on all the buildings at the factory complex shown below. the buildings have flat roofs. you charge according to the total roof area. what is this area, in square yards?

Solve the equation for x. 50(4x + 12) = 200