Answer: the rate uphill is 6 mph.
The rate downhill is 10 mph
Step-by-step explanation:
Let x represent the rate at which the jogger ran uphill.
The jogger runs 4 miles per hour faster downhill than uphill. This means that speed at which the jogger ran downhill is (x + 4) mph
Time = distance/speed
if the jogger can runs 5 miles downhill, then the time taken to run downhill is
5/(x + 4)
At the same time, the jogger runs 3 miles uphill. It means that the time taken to run uphill is
3/x
Since the time is the same, it means that
5/(x + 4) = 3/x
Cross multiplying, it becomes
5 × x = 3(x + 4)
5x = 3x + 12
5x - 3x = 12
2x = 12
x = 12/2
x = 6
The rate downhill is 6 + 4 = 10 mph
Answer:
15
Step-by-step explanation:
Add the total of miles Marisa is going to drive; 200 + 220 = 420
Next, divide the total miles by the average miles Marisa can travel on one gallon of gas; 420 / 28 = 15
(Hope this helps!)
Answer:
x = -8
Step-by-step explanation:
x = 2y - 4 --- Equation 1
7x + 5y = -66 --- Equation 2
I will be using the substitution method to solve this.
Substitute x = 2y - 4 into Equation 2:
7x + 5y = -66
7(2y - 4) + 5y = -66
Evaluate.
14y - 28 + 5y = -66
Evaluate like terms.
19y - 28 = -66
Isolate 19y.
19y = -66 + 28
= -38
Find y.
y = -38 ÷ 19
y = -2 --- Equation 3
Substitute y = -2 into Equation 1:
x = 2y - 4
x = 2(-2) - 4
Evaluate.
x = -4 - 4
x = -8
14 hundreds, 10 tens, and 2 ones.