Question

X ²+9X+8=0 (R:-1e-8)

Answer 1

Δ=b²-4ac
Δ=9²-4.1.8
Δ=81-32
Δ=49

X= -b±√Δ / 2a 
x= -9±√49 / 2.1
x= -9±7/2
xI= -9+7/2=-2/2=-1
xII= -9-7/2=-16/2=-8