X + 3y = 18
-X - 4y = -25

x = -3

y= 7

Step-by-step explanation:

x + 3y=18 (1)

-x - 4y=-25 (2)

from equation (1)

x = 18 - 3y ---(3)

putting equation (3) into equation (2)

-(18 - 3y) - 4y = -25

18 + 3y -4y = -25

3y - 4y = -25 - 18

-y = -7

y = 7 ✓

Putting y=7 into equation (1)

x + 3(7) = 18

x + 21 = 18

x = 18 - 21

x = -3 ✓

i need more information

step-by-step explanation:

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