Question

quais são as raises da equacao x2-10x+21=0

Answer 1

x² - 10x + 21 = 0

a = 1 b = -10 c = 21

b² - 4•a•c
-10² - 4•1•21
100 - 84 = 16

-b ± √∆.
_______ =
2•a

-(-10) + √16 10 + 4
x1 = __________ = ______ = 7
2•1 2
-(-10) - √16 10 - 4
x2 = __________ = ______ = 3
2•1 2

S = { 3,7 }