document.write( "Question 499304: I need to find the solution to the equation $\"+160z%5E2=640+\"$ by factoring. I know the first step is to set the equation equal to zero by subtracting 640 from both sides, leaving me with $\"+160z%5E2-640=0+\"$ , and I then factored out the common factor, 80. I now have $\"+80%282z%5E2-8%29=0+\"$ . I don't know where to go from there. \n" ); document.write( "

Algebra.Com's Answer #337537 by chessace(471) $\"\"$ $\"About$

You can put this solution on YOUR website!
First, 2 and 8 are both even, so 160 was a better factor.
\n" ); document.write( "And that factor can be thrown out (divide both sides by it).
\n" ); document.write( "So you are left with z^2-4=0
\n" ); document.write( "Factor that by recalling that (z+a)(z-a)=z^2-a^2
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