Express as a polynomial (2x+10y)^3 (2x + 10y)3 This can be done by the binomial theorem. If that is the way you were told to do it, post again. I will only show you the basic method, which gives the same answer. Write the cube as multiplication three times (2x + 10y)(2x + 10y)(2x + 10y) Use FOIL to multiply out the second and third parentheses: (2x + 10y)(4x2 + 20xy + 20xy + 100y2) Collect terms in the second parentheses (2x + 10y)(4x2 + 40xy + 100y2) Use the distributive principle to multiply the two terms in the first parentheses by the trinomial in the second parentheses. 2x(4x2 + 40xy + 100y2) + 10y(4x2 + 40xy + 100y2) then distribute each: 8x3 + 80x2y + 200xy2 + 40x2y + 400xy2 + 1000y3 Collect like terms: 8x3 + 120x2y + 600xy2 + 1000y3 Edwin AnlytcPhil@aol.com