Question

solve t when t^2-2t=20

Answer 1

t^2-2t=20
t^2-2t-20=0
t= -(-2)+((-2)^2-4(1)(-20))^1/2/2(1)
=2+((4-80)^1/2)/2
=2+((-76)^1/2)/2
=1+((-19)^1/2)
(-19)^1/2 does not exist
So there is no solution for the answer

Answer 2

t^2-2t-20
t={2+-√4+80}\2
t=2(1+-√21)/2
t=1+-√21