Question 330426
let side =x

..
the increased length = x+8
Area = (x+8)(x+8)=225
x^2+16x+64=225
x^2+16x-159=0
find the roots of the equation by the quadratic formula
{{{x=(-b+-sqrt(b^2-4*a*c))/2a}}}
{{{x1=(-b+sqrt(b^2-4*a*c))/2a}}}
a=1,b=16,c-159
{{{x=(-16+sqrt(256+4*1*159))/2}}}

x1=6.933 the original length of square

similarly x2 = -22.9 ignore