Answer:
9x
Step-by-step explanation:
-4.5X(-2)
-4.5x * -2
9x
Answer: north 80 m/s
Explanation:
speed = distance/time = 56/0.7 = 80
Recall that velocity is composed of both the speed and the direction. In this case, the arrow is traveling 80 m/s to the north
1,000 miles is the total length of the trip
Cramer's rule works as follows:
x+3y=16
3x+y=8
Then
x=Dx/D
y=Dy/D
where Dx,Dy,D are 2x2 matrices formed from of coefficients and right hand side.
D=
1 3
3 1
=1-9=-8
Dx=matrix D with first column replaced by the vector [16,8]=
16,3
8 1
=16-24
=-8
Dy=matrix D with second column replaced by the vector [16,8]=
1 16
3 8
=8-48
=-40
Therefore
x=-8/-8=1
y=--40/-8=5
Check:
x+3y=1+3(5)=16
3x+y=3(1)+5=8 ok.
