Respostas

2013-11-16T11:53:08-02:00
A = Altura
b = Base

b.a = 30 m²

(b+1)*(a+1) = 30 + 12
(b+1)*(a+1) = 42
b * a + b + a + 1 = 42
30 + b + a + 1 = 42
b + a = 42 - 30 - 1
b + a = 11

x² - 11x + 30 = 0

Δ = b² - 4 a c
Δ = 11² - 4 * 1 * 30
Δ = 121 - 120
Δ = 1

x = b ± √Δ / 2
x = 11 ± 1 / 2

x' = 11 + 1 = 12 / 2 = 6 metros
x'' = 11 - 1 = 10 / 2 = 5 metros
6 3 6