Answer:
240 miles
Step-by-step explanation:
Step 1
We find the constant rate at which the family travels
Speed(Rate) = Distance/Time
A Family travels at a constant rate and drove 420 miles in 7 hours.
Speed(Rate) = 420 miles/7 hours
= 60 miles per hour
Step 2
If they drive at the same speed ,How many miles will they drive in the next four hours.?
We are to finally calculate the distance for the next 4 hours
Distance = Speed × Time
Speed = 60 miles per hour
Time = 4 hours
Distance = 60 miles per hour × 4 hours
Distance = 240 miles
Therefore, for the next 4 hours the number of miles they would drive is 240 miles
#1)
Answer:
x=1 and y=12
Explanation:
y=5x+7
y=2x+10
This system should use substitution because the value of y is given in terms if x.
Substitution:
5x+7=2x+10
Solve:
3x=3
x=1
Substitute x to solve for y by plugging x into one if the original equations(doesn’t matter which one is used).
y=5x+7
y=5(1)+7
y=5+7
y=12
#2)
Answer:
x=-8 and y=2
Explanation:
y=2x+18
9y=-2x+2
This system also uses substitution. The value of y us already given in terms if c in the first equations, so we will substitute in the second equation.
Substitute:
9(2x+18)=-2x+2
Solve:
18x+162=-2x+2
20x=-160
x=-8
Now that we have the value if x, plug it into one of the original equations(doesn’t matter which equation) and substitute to find y.
y=2x+18
Substitute:
y=2(-8)+18
Solve:
y=-16+18
y=2
Answer:
Step-by-step explanation:
To find the value of an exterior angle of a regular polygon, we can apply a formula.
Just saying, this angle is a 45 degree angle.
and the X on both is '-1'
I think?
hope this helps. im not good at math..- :)
Suppose:
C=cost
c=cost per kilo-watt hour
w=number of watts
h=number of hours
thus
C=kwhc
where:
k=constant of proportionality:
k=C/(whc)
but
C=15 when w=6000, h=10/60=1/6 hours, c=7.5 cents per kw/h
thus
k=15/(6000*1/6*7.5)
k=0.002
thus:
C=0.002(whc)
hence:
when
h=70*2=140=140/6=70/3 hours the cost will be:
C=0.002(6000*70/3*7.5)
C=2100 cents
C=$21
