Area is Length x width:
(2x+5) * x = 420
Distributive property:
2x^2 +5x = 420
Subtract 420 from both sides:
2x^2 + 5x - 420 = 0
Using the quadratic formula:
a = 2, b = 5, c = -420:
-5 +/ √5^2 -4*(2*-420) / 2*2
x = 13.2951
Rounded to the nearest hundredth = 13.30 inches.
