Question

achar as raízes das equações:
a) x2-×-20=0
b) x2-3×-4=0
c)×2-8+7=0
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Answer 1

a) DELTA = (-1)^2 - 4*1*(-20)
DELTA = 1 + 80
DELTA = 81

x’ = -(-1) + RAIZ QUADRADA(81)/2*1
x’ = (1 + 9)/2 = 5


x’’ = -(-1) - RAIZ QUADRADA(81)/2*1
x’’ = (1 - 9)/2 = -4

b) DELTA = (-3)^2 - 4*1*(-4)
DELTA = 9 + 16 = 25


x’ = -(-3) + RAIZ QUADRADA(25)/2*1
x’ = (3 + 5)/2 = 4


x’’ = -(-3) - RAIZ QUADRADA(25)/2*1
x’’ = (3 - 5)/2 = -1

c) DELTA = (-8)^2 - 4*1*(7)
DELTA = 64 - 28 = 36


x’ = -(-8) + RAIZ QUADRADA(36)/2*1
x’ = (8 + 6)/2 = 7


x’’ = -(-8) - RAIZ QUADRADA(36)/2*1
x’’ = (8 - 6)/2 = 1