I need help with algebra 2 pleasee

Step-by-step explanation:

We can add 9 to both sides of the equation to get .

We can divide both sides of the equation by 21 to get .

We take the square root of both sides of the equation to get .

However, that isn't in the form we need.

We know that

so the answer is really and we're done!

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

i belive those are the ones that are under 90 degreese.