SOLUTION: How do I know when a term is squared in multiplying binomials with special cases? For example: I got this one right on my homework. (3x-2)^2 is 9x^2-12x+4 but a similar pro

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: How do I know when a term is squared in multiplying binomials with special cases? For example: I got this one right on my homework. (3x-2)^2 is 9x^2-12x+4 but a similar pro      Log On


   



Question 414392: How do I know when a term is squared in multiplying binomials with special cases?
For example: I got this one right on my homework.
(3x-2)^2 is 9x^2-12x+4
but a similar problem that I had was marked wrong, because I did not square the last term. That problem was
(2r-3s)^2
I had answered it as 4r^2-12rs-9s. However, my teacher wrote the correct answer by it and she wrote 4r^2-12rs-9s^2. Is it only squared if there is a variable involved? Or is there another way to tell when to square the last term? Thank you in advance

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
You're squaring it no matter what. In the first example, you squared -2 to get


%28-2%29%5E2=%28-2%29%2A%28-2%29=4


In the second example, you should have squared -3s to get


%28-3s%29%5E2=%28-3s%29%28-3s%29=%28-3%2A%28-3%29%29%2A%28s%2As%29=9s%5E2


If you need more help, email me at jim_thompson5910@hotmail.com

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Jim