How do you find all the real and complex roots of $x^2 - 20 = 0$ ?

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Answer 1 · 2016-01-10T16:32:13

roots are real $x = ±2sqrt5$
There are no complex roots

$x^2 - 20 = 0 rArr x^2 = 20 rArr x = ±sqrt20$

now $sqrt20 = sqrt(4 xx 5 ) = 2 sqrt5$

How do you find all the real and complex roots of x^2 - 20 = 0x^2 - 20 = 0?