Question 1076979
width is x, length ix 3x, area is 3x^2
2x*(3x+1)=6x^2+2x, and subtract 56=3x^2, the original area
3x^2+2x-56=0
a=3, b=2, c=-56
x=(1/6)(-2+/- sqrt(4+672)); sqrt 676=26
x=(1/6)(24), take positive root only, and x=4
width 4 
length is 12
area is 48
width 8 and length 13, area is 104, which is 56 more.