Answer:
width = 15 ft
length = 26 ft
Step-by-step explanation:
(19 - 2x)(30 - 2x) = 390
570 - 38x - 60x + 4x² = 390
combine like terms:
4x² - 98x + 570 = 390
subtract 390 from each side of the equation:
4x² - 98x + 180 = 0
divide by 4:
x² - 24.5 + 45 = 0
(x - 22.5)(x - 2) = 0
x = 22.5 and x = 2
since x = 22.5 is out of the usable range, x = 2 ft is the solution
width = 19 ft - 4 ft = 15 ft (remember that there will be a 2 ft gap at each wall, thus subtract 4 ft)
length = 30 ft - 4 ft = 26 ft
