Evaluate the expression below when x= -1. 2x2 - 5 x + 9

2x^2-5=-3

X+9=8

Step-by-step explanation:

Assuming those are 2 expressions:

2x^2-5

=2(-1)^2-5

=2-5

=-3

X+9

=-1+9

=8

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

77

step-by-step explanation: