Question 729293
x = length
y = width
x = -1+3y
d = diagonal


AREA, {{{(3y-1)y=24}}}
FIND DIAGONAL, d.
{{{d^2=x^2+y^2}}}
{{{d^2=(3y-1)^2+y^2}}}
{{{d=sqrt((3y-1)^2+y^2)}}}


Using area equation, first find y.
{{{3y^2-y=24}}}
{{{3y^2-y-24=0}}}
for practical purposes, {{{highlight(y=3)}}}.  (used general quadratic solution formula).


Using formula just found for d, diagonal, {{{d=sqrt((3*3-1)^2+3*3)}}}, {{{highlight(d=sqrt(73))}}}, the Diagonal.