Question

6. Determine as zeros dos equaces do Zgrou completas do a formula de Bhaskara
a)x² - x - 20=0
b)x² -3x -4=0
c)x² - 8x + 7=0​

Answer 1

Resposta:

Explicação passo-a-passo:

a)x² - x - 20=0

Δ= -1² - 4 × 1 × (-20)

Δ= 1 + 80 = 81

X= - (-1) ± √81 / 2 × 1

x= 1 ± 9 / 2

x'= 1 + 9 / 2 = 10 / 2 = 5

x" = 1 - 9 / 2 = -8 / 2 = -4

b)x² -3x -4=0

Δ= -3² - 4 × 1 × (-4)

Δ= 9 + 16 = 25

X= - (-3) ± √25 / 2 × 1

x= 3 ± 5 / 2

x'= 3 + 5 / 2 = 8 / 2 = 4

x" = 3 - 5 / 2 = -2 / 2 = -1

c)x² - 8x + 7=0​

Δ= -8² - 4 × 1 × 7

Δ= 64 -28 = 36

X= - (-8) ± √36 / 2 × 1

x= 8 ± 6 / 2

x'= 8 + 6 / 2 = 14 / 2 = 7

x" = 8 - 6 / 2 = 2 / 2 = 1