Solve the following inequality.
x2 + 18x + 80 < 0

I dont really know the answer but you can find the answer in Mathpapa.com there's a free calculator for the algebra but the answer is -10 < x < -8

Hope this helps!

The step by step explanation is also on there if you need more help understanding

since the airplane is moving with constant speed then the distance travelled can be calculated by x=u*t

in km/h would be:

x=640*3.5=2.240 km

in m/s would be:

u=640 km/h= 640.000 m/h =640.000/ 3600 m/s =177.8 m/s

t= 3.5 h= 3.5 * 3600 s=12.600 s

then x=u*t= 177.8*12.600= 2.240.280 m