document.write( "Question 547170: Factor completely:\r
\n" ); document.write( "\n" ); document.write( "4y^2-12y+9-z^2\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So, I tried but I'm stuck. Here's my work so far.\r
\n" ); document.write( "\n" ); document.write( "(4y^2-z^2)+(9-12y)
\n" ); document.write( "(2y-z)^2 + 3(3-4y)\r
\n" ); document.write( "\n" ); document.write( "I'm not sure if it's at all correct.
\n" ); document.write( "

Algebra.Com's Answer #356277 by bucky(2189)\"\" \"About 
You can put this solution on YOUR website!
You were on the right track.
\n" ); document.write( ".
\n" ); document.write( "Given to factor:
\n" ); document.write( ".
\n" ); document.write( "\"4y%5E2-12y%2B9-z%5E2+\"
\n" ); document.write( ".
\n" ); document.write( "Separate the first three terms as follows:
\n" ); document.write( ".
\n" ); document.write( "\"%284y%5E2-12y+%2B+9%29+-+z%5E2\"
\n" ); document.write( ".
\n" ); document.write( "Note that the terms in the parentheses are an algebraic expression that is a perfect square. It can be factored as shown below:
\n" ); document.write( ".
\n" ); document.write( "\"%282y+-+3%29%5E2+-z%5E2\"
\n" ); document.write( ".
\n" ); document.write( "Notice now that this new form is the difference between two squares. Recall the rule for the difference of two squares:
\n" ); document.write( ".
\n" ); document.write( "\"a%5E2+-+b%5E2+=+%28a+-+b%29%2A%28a%2Bb%29+\"
\n" ); document.write( ".
\n" ); document.write( "For your problem \"a+=+%282y-3%29\" and \"b+=+z\"
\n" ); document.write( ".
\n" ); document.write( "Substitute these into the rule for the difference of two squares as shown in the steps that follow:
\n" ); document.write( ".
\n" ); document.write( "\"a%5E2+-+b%5E2+=+%28a+-+b%29%2A%28a%2Bb%29\"
\n" ); document.write( ".
\n" ); document.write( "\"%282y-3%29%5E2+-+z%5E2+=+%28%282y+-+3%29-z%29%2A%28%282y+-+3%29%2Bz%29\"
\n" ); document.write( ".
\n" ); document.write( "Remove the interior parentheses on the right side of this equation and you have:
\n" ); document.write( ".
\n" ); document.write( "\"%282y-3%29%5E2+-+z%5E2+=+%282y+-+3-z%29%2A%282y+-+3%2Bz%29\"
\n" ); document.write( ".
\n" ); document.write( "The right side is the factored form of the problem that you were given. So you can write the answer to this problem in the equation form:
\n" ); document.write( ".
\n" ); document.write( "\"4y%5E2-12y%2B9-z%5E2+=+%282y+-+3-z%29%2A%282y+-+3%2Bz%29\"
\n" ); document.write( ".
\n" ); document.write( "or maybe you want to rearrange the terms in the parentheses a little so the letters come first as in:
\n" ); document.write( ".
\n" ); document.write( "\"4y%5E2-12y%2B9-z%5E2+=+%282y-z+-+3%29%2A%282y+%2Bz-+3%29\"
\n" ); document.write( ".
\n" ); document.write( "Whatever your teacher prefers. It's just a matter of preference, but the rearrangement is probably the most commonly used form.
\n" ); document.write( ".
\n" ); document.write( "Hope this helps you understand the problem a little better.
\n" ); document.write( ".
\n" ); document.write( "
\n" );