The width of a rectangle, in feet, is represented by (3x-1.5). The length of the rectangle, in feet, is represented by (1.25x+3). Find the perimeter.

5.5x + 1.5

Step-by-step explanation:

P = 2(l + w)

P = 2(1.25x + 3 + 3x - 1.5)

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