Let the width be x
The lenght will be 4x-23
The area is lenghtX width, so:
x(4x-23) = 72
4x² -23x -72=0
Using the quadratic formula:
[tex]\begin{gathered} x=\frac{-b\pm\sqrt[\square]{b^{2}-4ac}}{2a} \\ x=\frac{23\pm\sqrt[\square]{529+1152_{}}}{8} \\ x=\frac{23\pm41}{8} \\ x1=8 \\ x2=-18/8 \end{gathered}[/tex]We'll use the value of x1, because we're looking for a measure, so it has to be positive.
Then, the width is 8cm. The lenght is 4*8-23= 9cm.
