Problema Solution
A school designer wants to create a whiteboard with the optimal dimensions to enhance learning. It is determined that if one side of the whiteboard is x + 5y inches, the other side should be inches. Write an algebraic expression for the area of such a whiteboard, simplify it, and include correct units with the solution.
Answer provided by our tutors
Area of a rectangle = side times side
so here, area = (x + 2y) times (x^2 -2xy+9y^2 ) square inches
do the x first:
x times (x^2 -2xy+9y^2 ) = x^3 - 2x^2y + 9y^2
Now do the 2y
2y times (x^2 -2xy+9y^2 ) = 2x^2y - 4xy^2 + 18y^3
Now add all the bits up:
area = x^3 + 5xy^2 + 18y^3 square inches