Question 77224
*[invoke quadratic_factoring 16, 40, 25]

So if we added a y term to the factorization we get:


{{{(4x+5y)(4x+5y)}}}

which can be written as:

{{{(4x+5y)^2}}}

Notice how {{{(4x+5y)(4x+5y)}}} foils back to 

{{{16x^2 + 40xy + 25y^2}}}