Answer:a)117 hours b)4.875days.
Step-by-step explanation:
Using the formula
Speed =Distance / Time
Given Distance = 3 3/5 -mile
and Speed=2/65 miles per hour.
Time =Distance / Speed
Time = (3 3/5)/(2/65)
Time =18/5÷2/65
Time =18/5 x 65/2 =117 hours
Now 24 hours =1 day
therefore 117hours =(117hours x 1 day )/ 24 =4.875days.
1)
I:x-y=-7
II:x+y=7
add both equations together to eliminate y:
x-y+(x+y)=-7+7
2x=0
x=0
insert x=0 into II:
0+y=7
y=7
the solution is (0,7)
2)
I: 3x+y=4
II: 2x+y=5
add I+(-1*II) together to eliminate y:
3x+y+(-2x-y)=4+(-5)
x=-1
insert x=-1 into I:
3*-1+y=4
y=7
the solution is (-1,7)
3)
I: 2e-3f=-9
II: e+3f=18
add both equations together to eliminate f:
2e-3f+(e+3f)=-9+18
3e=9
e=3
insert e=3 into I:
2*3-3f=-9
-3f=-9-6
-3f=-15
3f=15
f=5
the solution is (3,5)
4)
I: 3d-e=7
II: d+e=5
add both equations together to eliminate e:
3d-e+(d+e)=7+5
4d=12
d=3
insert d=3 into II:
3+e=5
e=2
the solution is (3,2)
5)
I: 8x+y=14
II: 3x+y=4
add I+(-1*II) together to eliminate y
8x+y+(-3x-y)=14-4
5x=10
x=2
insert x=2 into II:
3*2+y=4
y=4-6
y=-2
the solution is (2,-2)
The product of -8. (-8)= 64
We know that C is 385, so we can plug that in to get the equation 385=15n+85. To find the number of watches, we have to solve for n.
To do that we have to...
385=15n+85
First subtract both sides of the equal sign by 85 (because we need to do the opposite)
300=15n (because 85-85 is zero, so we eliminated that, and 385-85 is 300)
Now we divide both sides of the equal sign by 15 (again, opposites)
20=n (because 15n/15 leaves us with n since both 15s cancel out, and 300/15 is 20)
So the number of watches made were 20.
