use quadratic formula
(-b +- (sqrt(b^2-4ac) ) / 2a
a=1
b=-8
c=41
1.
(8 + sqrt(64-4*1*41) ) / 2*1
4 + sqrt(-100) / 2
4 + 5i.......................... solution 1
2.
(8 - sqrt(64-4*1*41) ) / 2*1
4 - sqrt(-100) / 2
4 - 5i.......................... solution 2