Answer:
x = 3
Step-by-step explanation:
Given:
Required:
Value of x and length of segment LM
SOLUTION:
Since M is the midpoint of line segment LN, it implies that:
(substitution)
Combine like terms
Divide both sides by 2
Plug in the value of x
Answer: radius = 6.18 (I don't know what solutions you have, but the actual answer for the radius is about 6.18 cm so which ever is closest.)
Step-by-step explanation:
the area of a circle is \pi r^{2}
*rewrite your equation solving for radius
r=\sqrt{A/\pi } =\sqrt{120/\pi } = 6.18
Answer:
Step-by-step explanation:
Perpendicular bisector of the chord connecting the the points (-1,2) and (2,3) is also passing through the center of the circle.
We'll find the equation of the line and solve the system to find the center.
<u>Midpoint of the chord:</u>
- ((-1 + 2)/2, (2 + 3)/2) = (0.5, 2.5)
<u>Equation of the line through chord (-1,2) and (2,3):</u>
- m = (3 - 2)/(2 + 1) = 1/3
- y - 2 = 1/3(x + 1)
- y = 1/3x + 7/3
<u>Perpendicular bisector is:</u>
- y - 2.5 = -3(x - 0.5)
- y = -3x + 4 >> (1)
<u>And the given line is:</u>
- 2x - 3y + 1 = 0
- y = 2/3x + 1/3 >> (2)
<u>Solve the system:</u>
- -3x + 4 = 2/3x + 1/3
- -9x + 12 = 2x + 1
- 11x = -11
- x = -1
<u>Find y:</u>
- y = -3(-1) + 4 = 3 + 4 = 7
The center is (-1, 7)
<u>Find the radius, the distance from center to one of points on circle </u>
- (-1, 7) and (-1, 2)
- 7 - 2 = 5
<u>The equation of circle is:</u>
- (x + 1)² + (y - 7)² = 5²
- (x + 1)² + (y - 7)² = 25
Distributive
2(3+4+8+7)
(2x3)+(2x4)+(2x8)+(2x7
6+8+16+14
=44
Non-Distributive
2(3+4+8+7)
Add all the number in parenthesis
3+4=7+8=15+7=22
2(22)
=44
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.