document.write( "Question 210629: f(x) = 7x2 - 2 how do I use the Quadratic Formula to find the x-intercepts of this equation? \n" ); document.write( "
Algebra.Com's Answer #159141 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
\"f%28x%29+=+7x%5E2+-+2\" Start with the given function.\r
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\n" ); document.write( "\n" ); document.write( "\"0+=+7x%5E2+-+2\" Plug in \"f%28x%29=0\"\r
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\n" ); document.write( "\n" ); document.write( "Notice that the quadratic \"7x%5E2-2\" is in the form of \"Ax%5E2%2BBx%2BC\" where \"A=7\", \"B=0\", and \"C=-2\"\r
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\n" ); document.write( "\n" ); document.write( "Let's use the quadratic formula to solve for \"x\":\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%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( "\"x+=+%28-%280%29+%2B-+sqrt%28+%280%29%5E2-4%287%29%28-2%29+%29%29%2F%282%287%29%29\" Plug in \"A=7\", \"B=0\", and \"C=-2\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%280+%2B-+sqrt%28+0-4%287%29%28-2%29+%29%29%2F%282%287%29%29\" Square \"0\" to get \"0\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%280+%2B-+sqrt%28+0--56+%29%29%2F%282%287%29%29\" Multiply \"4%287%29%28-2%29\" to get \"-56\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%280+%2B-+sqrt%28+0%2B56+%29%29%2F%282%287%29%29\" Rewrite \"sqrt%280--56%29\" as \"sqrt%280%2B56%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%280+%2B-+sqrt%28+56+%29%29%2F%282%287%29%29\" Add \"0\" to \"56\" to get \"56\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%280+%2B-+sqrt%28+56+%29%29%2F%2814%29\" Multiply \"2\" and \"7\" to get \"14\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%280+%2B-+2%2Asqrt%2814%29%29%2F%2814%29\" Simplify the square root (note: If you need help with simplifying square roots, check out this solver) \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+sqrt%2814%29%2F7\" or \"x+=+-sqrt%2814%29%2F7\" Break up the expression and reduce. \r
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\n" ); document.write( "\n" ); document.write( "So the solutions are \"x+=+sqrt%2814%29%2F7\" or \"x+=+-sqrt%2814%29%2F7\"
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