Question 278634
4*5=20 ft^2
(4+x)+(5+x)=30 ft^2
20+9x+x^2=30

x^2+9x-10=0
(x+10)*(x-1)=0
x=1
check
5*6=30
ok
add one foot border to each side.
*[invoke quadratic "x", 1, 9, -10 ]