document.write( "Question 612999: (1-i)(7+2i) \n" ); document.write( "
Algebra.Com's Answer #385847 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
\"%281-i%29%2A%287%2B2i%29\" Start with the given expression.\r
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\n" ); document.write( "\n" ); document.write( "\"%281%29%287%29%2B%281%29%282i%29%2B%28-i%29%287%29%2B%28-i%29%282i%29\" FOIL.\r
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\n" ); document.write( "\n" ); document.write( "\"7%2B2i-7i-2i%5E2\" Multiply.\r
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\n" ); document.write( "\n" ); document.write( "\"7%2B2i-7i-2%28-1%29\" Replace \"i%5E2\" with \"-1\". Note: \"i%5E2=-1\".\r
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\n" ); document.write( "\n" ); document.write( "\"7%2B2i-7i%2B2\" Multiply.\r
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\n" ); document.write( "\n" ); document.write( "\"9-5i\" Combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "So \"%281-i%29%2A%287%2B2i%29=9-5i\".\r
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\n" ); document.write( "\n" ); document.write( "So the expression is now in standard form \"a%2Bbi\" where \"a=9\" and \"b=-5\"
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