the answer could be
x =(8-√-776)/14=(4-i√ 194 )/7= 0.5714-1.9898i or
x =(8+√-776)/14=(4+i√ 194 )/7= 0.5714+1.9898i
why?
because
a=7
b=-8
c=30
If ax2 + bx + c = 0,then x =(8-√-776)/14=(4-i√ 194 )/7= 0.5714-1.9898i or
x =(8+√-776)/14=(4+i√ 194 )/7= 0.5714+1.9898i
use this formula to see the solution...... x = -b ± b2 - 4ac
2a