Question

base vezes altura do retângulo x+2 3x-1

Answer 1

A = base x altura
A =  (X + 2) (3 X - 1)
A =3 X² + 5 X - 2
Δ = b² - 4 .a c
Δ = 5² - 4 . 3 . -2
Δ = 25 + 24
Δ = 49
\/¨¨49 = 7
x = -b +ou- 7/2.3
x = -5 +ou-7/6
x´= -5 + 7 /6
x´= 2/6 ⇒1/3
x" = -5-7/6
x" = -12/6
x" =-2
3.(-2)² + 5 . - 2 - 2
3 . 4 -10 -2
12 -10 -2
12 -12 =0
S={-2,1/3}