Question

.....

*****

7x²-2x-1=0

Answer 1

Boa noite

7x² - 2x - 1 = 0

delta
d² = 4+ 4*7*1 = 32
d = 4√2

x1 = (2 + 4√2)/14 = (1 + 2√2)/7 
x2 =  (2 - 4√2)/14 = (1 - 2√2)/7