<PRE><B>Question 821654</B>
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x = y + 3
15 = sqrt( xx + yy )
225 = xx + yy
225 = (y + 3)(y + 3) + yy
225 = yy + 6y + 9 + yy
2yy + 6y - 216 = 0
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the above quadratic equation is in standard form, with a=2, b=6, and c=-216
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to solve the quadratic equation, by using the quadratic formula, copy and paste this:
2 6 -216
into this solver: https://sooeet.com/math/quadratic-equation-solver.php
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the two real roots (i.e. the two x-intercepts), of the quadratic are:
y = 9
y = -12
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negative width doesn&#39;t make sense so use the positive root:
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answer:
w= 9 cm
L= 12 cm
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Solve and graph linear equations:
https://sooeet.com/math/linear-equation-solver.php
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Solve quadratic equations, quadratic formula:
https://sooeet.com/math/quadratic-formula-solver.php
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Solve systems of linear equations up to 6-equations 6-variables:
https://sooeet.com/math/system-of-linear-equations-solver.php</PRE>