Question

X elevado a 2 - X - 42 = 0

???

Answer 1

x^2 - x - 42 = 0

a = 1
b = - 1
c = - 42

Delta = b^2 - 4.a.c
Delta = (- 1)^2 - 4.1.(- 42)
Delta = 1 + 168
Delta = 169

x = - b +- VDelta / 2.a
x = - (- 1) +- V169 / 2.1
x = 1 +- 13 / 2

x' = 1 - 13 / 2
x' = - 12/2
x' = - 6

x" = 1 + 13 / 2
x" = 14/2
x" = 7

S = {- 6, 7}