Resposta:
a) x1 = -1/2 // x2 = -3/2
b) x1 = x2 = 2
c) x1 = 2 // x2 = 1/3
d) x1 = 2 // x2 = 1/5
e) x1 = -3 // x2 = 1/4
Explicação passo-a-passo:
a) 4x² + 8x + 3 = 0
a = 4 / b = 8 / c = 3
∆ = b² - 4ac = 8² - 4 • 4 • 3 = 16
x = (-8 ± 4) / 8
x1 = -1/2 // x2 = -3/2
b) 2x² - 8x + 8 = 0 -> 2 (x² - 4x + 4) -> 2 (x - 2)²
a = 2 / b = -8 / c = 8
∆ = b² - 4ac = (-8)² - 4 • 2 • 8 = 0
x = (8 ± 0) / 4
x1 = x2 = 2
c) 3x² - 7x + 2 = 0
a = 3 / b = -7 / c = 2
∆ = b² - 4ac = (-7)² - 4 • 3 • 2 = 25
x= = (7 ± 5) / 6
x1 = 2 // x2 = 1/3
d) 5x² - 11x + 2 = 0
a = 5 / b = -11 / c = 2
∆ = b² - 4ac = (-11)² - 4 • 5 • 2 = 81
x = (11 ± 9) / 10
x1 = 2 // x2 = 1/5
e) 4x² + 11x - 3 = 0
a = 4 / b = 11 / c = -3
∆ = b² - 4ac = 11² - 4 • 4 • (-3) = 169
x = (-11 ± 13) / 8
x1 = -3 // x2 = 1/4
