document.write( "Question 823125: Find the value(s) of x in the domain of f(x)= -x^2+4x+1 for which f(x) = -4. Please show all work.\r
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Algebra.Com's Answer #495282 by TimothyLamb(4379)\"\" \"About 
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\n" ); document.write( "f(x) = -x^2 + 4x + 1
\n" ); document.write( "for f(x) = -4
\n" ); document.write( "-x^2 + 4x + 1 = -4
\n" ); document.write( "-x^2 + 4x + 5 = 0
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\n" ); document.write( "the above quadratic equation is in standard form, with a=-1, b=4, and c=5
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\n" ); document.write( "to solve the quadratic equation, by using the quadratic formula, copy and paste this:
\n" ); document.write( "-1 4 5
\n" ); document.write( "into this solver: https://sooeet.com/math/quadratic-equation-solver.php
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\n" ); document.write( "this quadratic has two real roots (the x-intercepts), which are:
\n" ); document.write( "x = -1
\n" ); document.write( "x = 5
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\n" ); document.write( "negative length doesn't make sense for this problem, so use the positive root
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\n" ); document.write( "answer:
\n" ); document.write( "distance from the bottom of the ladder to building = 3 m
\n" ); document.write( "distance from the ground to the top of ladder = 4 m
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\n" ); document.write( "Solve and graph linear equations:
\n" ); document.write( "https://sooeet.com/math/linear-equation-solver.php
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\n" ); document.write( "Solve quadratic equations, quadratic formula:
\n" ); document.write( "https://sooeet.com/math/quadratic-formula-solver.php
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\n" ); document.write( "Solve systems of linear equations up to 6-equations 6-variables:
\n" ); document.write( "https://sooeet.com/math/system-of-linear-equations-solver.php \n" ); document.write( "
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