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.
The formula<span> for the </span>equation<span> of a </span>circle<span> is (x – h)</span>2+ (y<span> – k)</span>2<span> = r</span>2<span>, where (h, k) represents the coordinates of the </span>center<span> of the </span>circle<span>, and r represents the radius of the </span>circle<span>. If a </span>circle<span> is </span>tangent<span> to the x-</span>axis<span> at (</span>3,0), this means it touches the x-axis at that point. hope this helps
- Ava<3
Answer:
Step-by-step explanation:
let x and y be length and width of rectangle.
Perimeter=2(x+y)
area=xy
2(x+y)=1/2 xy
4(x+y)=xy
4x+4y=xy
x y-4y=4 x
y(x-4)=4 x
If it the one that says which double fact should you use for
6+5
it would be 5+5
which is 10 and then you could add the 1
