Answer: Downhill:10mph Uphill:5mph
Step-by-step explanation:
We are looking for Dennis’s downhill speed.
Let
r=
Dennis’s downhill speed.
His uphill speed is
5
miles per hour slower.
Let
r−5=
Dennis’s uphill speed.
Enter the rates into the chart. The distance is the same in both directions,
20
miles.
Since
D=rt
, we solve for
t
and get
t=
D
r
.
We divide the distance by the rate in each row and place the expression in the time column.
Rate
×
Time
=
Distance
Downhill
r
20
r
20
Uphill
r−5
20
r−5
20
Write a word sentence about the time.
The total time traveled was
6
hours.
Translate the sentence to get the equation.
20
r
+
20
r−5
=6
Solve.
20(r−5)+20(r)
40r−100
0
0
0
=
=
=
=
=
6(r)(r−5)
6
r
2
−30r
6
r
2
−70r+100
2(3
r
2
−35r+50)
2(3r−5)(r−10)
Use the Zero Product Property.
(r−10)=0
r=10
(3r−5)=0
r=
5
3
The solution
5
3
is unreasonable because
5
3
−5=−
10
3
and his uphill speed cannot be negative. So, Dennis's downhill speed is
10
mph and his uphill speed is
10−5=5
mph.
Check. Is
10
mph a reasonable speed for biking downhill? Yes.
Downhill:
10 mph
5 mph⋅
20 miles
5 mph
=20 miles
Uphill:
10−5=5 mph
(10−5) mph⋅
20 miles
10−5 mph
=20 miles
The total time traveled was
6
hours.
Dennis’ downhill speed was
10
mph and his uphill speed was
5
mph.
<h3>
Answer: 135 inches</h3>
========================================================
Work Shown:
1 yard = 3 feet
3 yards = 9 feet (multiply both sides by 3)
3 yards + 2 feet = 9 feet + 2 feet = 11 feet
1 foot = 12 inches
11 feet = 132 inches (multiply both sides by 11)
11 feet + 3 inches = 132 inches + 3 inches = <u>135 inches</u>
Answer:20.25
Step-by-step explanation:
If you do 81 divided by 4
I think Im not sure
Answer:
<em>Parallel</em>
Step-by-step explanation:
The dotted lines are parallel because they have the same <u>gradient</u> to each other, this means the two dotted lines will <u>never</u> touch each other.
Have a great day <3
2x + 9 + 3x + x =
6x + 9 =
when u use : 6x + 9 u will have infinite solutions
when u use 6x + 8 u will have no solutions
when u use 5x + 7 u will have 1 solution
