Question 62252
What is the solution for (2a-3y)(2a+3y)
 
 Distribute the 1st term in the 1st parentheses into the second parentheses, then the second term into the second parentheses.
2a(2a+3y)-3y(2a+3y)  
(If your friends and teacher is calling this FOIL, it's because you are multiplying the First terms, then the Outer terms, then the Inner terms, and then the Last terms.)
2a(2a)+2a(3y)-3y(2a)-3y(3y)
{{{4a^2+6ay-6ay-9y^2}}}
Combine your like terms.
{{{highlight(4a^2-9y^2)}}}
Note that this is a special thing, when the binomials are exactly the same but one is added and one is subtracted, it results in the difference of the squares of the terms: {{{(a+b)(a-b)=a^2-b^2}}}
Happy Calculating!!!