document.write( "Question 208120This question is from textbook Elementary and intermediate algebra
\n" ); document.write( ": I am trying to solve the following equations but I am having trouble. \r
\n" ); document.write( "\n" ); document.write( "1. (x+h)(x+k)=0. Do I use the FOIL method x^2+xk+hx+hk=0\r
\n" ); document.write( "\n" ); document.write( "2. w^2+3w=18. I am not sure where to start with this one.
\n" ); document.write( " w^2+3w-18
\n" ); document.write( " w^2+6w-3w-18
\n" ); document.write( " w(w+6)-3(w+6)
\n" ); document.write( " -3w(w+6)
\n" ); document.write( "I am totally lost for solving 'w'. Can you help me?
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Algebra.Com's Answer #157445 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
1.\r
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\n" ); document.write( "\n" ); document.write( "You use the zero product property here. Simply set each factor equal to zero and solve for 'x' in each case.\r
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\n" ); document.write( "\n" ); document.write( "2. \r
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\n" ); document.write( "\n" ); document.write( "There are two ways to do this\r
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\n" ); document.write( "\n" ); document.write( "Method # 1 Factoring and the Zero Product Property\r
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\n" ); document.write( "\n" ); document.write( "\"w%5E2%2B3w=18\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "\"w%5E2%2B3w-18=0\" Subtract 18 from both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"%28w%2B6%29%28w-3%29=0\" Factor the left side (note: if you need help with factoring, check out this solver)\r
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\n" ); document.write( "\n" ); document.write( "Now set each factor equal to zero:\r
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\n" ); document.write( "\n" ); document.write( "\"w%2B6=0\" or \"w-3=0\" \r
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\n" ); document.write( "\n" ); document.write( "\"w=-6\" or \"w=3\" Now solve for w in each case\r
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\n" ); document.write( "\n" ); document.write( "So the solutions are \"w=-6\" or \"w=3\" \r
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\n" ); document.write( "\n" ); document.write( "Or...\r
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\n" ); document.write( "\n" ); document.write( "Method # 2 The Quadratic Formula\r
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\n" ); document.write( "\n" ); document.write( "\"w%5E2%2B3w=18\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "\"w%5E2%2B3w-18=0\" Subtract 18 from both sides.\r
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\n" ); document.write( "\n" ); document.write( "Notice that the quadratic \"w%5E2%2B3w-18\" is in the form of \"Aw%5E2%2BBw%2BC\" where \"A=1\", \"B=3\", and \"C=-18\"\r
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\n" ); document.write( "\n" ); document.write( "Let's use the quadratic formula to solve for \"w\":\r
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\n" ); document.write( "\n" ); document.write( "\"w+=+%28-B+%2B-+sqrt%28+B%5E2-4AC+%29%29%2F%282A%29\" Start with the quadratic formula\r
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\n" ); document.write( "\n" ); document.write( "\"w+=+%28-%283%29+%2B-+sqrt%28+%283%29%5E2-4%281%29%28-18%29+%29%29%2F%282%281%29%29\" Plug in \"A=1\", \"B=3\", and \"C=-18\"\r
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\n" ); document.write( "\n" ); document.write( "\"w+=+%28-3+%2B-+sqrt%28+9-4%281%29%28-18%29+%29%29%2F%282%281%29%29\" Square \"3\" to get \"9\". \r
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\n" ); document.write( "\n" ); document.write( "\"w+=+%28-3+%2B-+sqrt%28+9--72+%29%29%2F%282%281%29%29\" Multiply \"4%281%29%28-18%29\" to get \"-72\"\r
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\n" ); document.write( "\n" ); document.write( "\"w+=+%28-3+%2B-+sqrt%28+9%2B72+%29%29%2F%282%281%29%29\" Rewrite \"sqrt%289--72%29\" as \"sqrt%289%2B72%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"w+=+%28-3+%2B-+sqrt%28+81+%29%29%2F%282%281%29%29\" Add \"9\" to \"72\" to get \"81\"\r
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\n" ); document.write( "\n" ); document.write( "\"w+=+%28-3+%2B-+sqrt%28+81+%29%29%2F%282%29\" Multiply \"2\" and \"1\" to get \"2\". \r
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\n" ); document.write( "\n" ); document.write( "\"w+=+%28-3+%2B-+9%29%2F%282%29\" Take the square root of \"81\" to get \"9\". \r
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\n" ); document.write( "\n" ); document.write( "\"w+=+%28-3+%2B+9%29%2F%282%29\" or \"w+=+%28-3+-+9%29%2F%282%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "\"w+=+%286%29%2F%282%29\" or \"w+=++%28-12%29%2F%282%29\" Combine like terms. \r
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\n" ); document.write( "\n" ); document.write( "\"w+=+3\" or \"w+=+-6\" Simplify. \r
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\n" ); document.write( "\n" ); document.write( "So the solutions are \"w+=+3\" or \"w+=+-6\" \r
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\n" ); document.write( "\n" ); document.write( "Why am I showing you the quadratic formula when factoring clearly works here? It turns out that you cannot factor every quadratic. However, the quadratic formula can solve any quadratic.
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