Fifty pounds of a cement-and-sand mixture is 40% sand.
how many pounds of sand must be added for the resulting mixture to be 60% sand?

Write an inequality and solve each problem.for exercises 11 and 12, interpret the solution.

How to find the exponential function y=ca^x, with points (1,2) and (2,1)

The area of a rectangle is 10 cm^2. one side of the rectangle is x cm. express the perimeter of the rectangle in terms of x and show that this rectangle cannot have a perimeter of 12 cm. the perimeter of the rectangle in terms of x is __ cm