Question 862818
Simple algebra applied to rectangle.


A = 55 yd^2
L = length
w = width
k = 4 yd
m = the factor, 3
-


{{{L=-k+mw}}}.
{{{A=wL}}}.
Substitute for L in the A equation.
{{{w(mw-k)=A}}}
{{{mw^2-kw=A}}}
{{{highlight_green(mw^2-kw-A=0)}}}


WHAT NEXT?
Use the general solution of a quadratic equation to solve for w.  Substitute the given values for k, A, and m and compute w.  Use the now found value of w to compute L.