Question

Essay: Show all work. 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+2y inches, the other side should be x^2+3xy-4y^2 inches. Write an algebraic expression for the area of such a whiteboard, simplify it, and include correct units with your solution.
(x+2y)(x^2+3xy-4y^2)
x(x^2+3xy-4y^2) +2y(x^2+3xy-4y^2)
x(x^2)+x(3xy)+x(-4y^2)+2y(x^2)+2y(3xy)+2y(-4y^2)
x^3+3x^2y-4xy^2+2yx^2+6xy^2-8y^3
=x^3-8y^3+5yx^2-2xy^2

Is this right?

Answer 1

looks good!

Answer 2

ok thank you loads!!