Question

cuál es el resultado aplicando la fórmula general
x2 - 4x - 21 = 0​

Answer 1

x² - 4x - 21 = 0

a = 1

b = -4

c = -21

x = -b ± √b² - 4ac/ 2a

x = -(-4) ± √(-4)² - 4(1) (-21)/ 2(1)

x = 4 ± √16 + 84/2

x = 4 ± √100/2

x1 = 4 + 10/2 = 14/2 = 7

x2 = 4 - 10/2 = -6/2 = -3

R// x1 = 7; x2 = -3

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