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What are the exact solutions of x^2 − x − 4 = 0?

1 Answer

1 vote
x= 0.5 + √(17)/2, x= 0.5 - √(17)/2

Working:
x^2 - x - 4 = 0
x^2 - x = 4
(x - 0.5)^2 - (0.5)^2 = 4
(x - 0.5)^2 = 4.25
x - 0.5 = ±√(17/4)
x = 0.5 ± √(17)/2
User Peter Hoeg
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