Answer:
We need to find the circumference, and in order to find the circumference we must know the formula for it.
Formula for circumference of a circle;
a = 2πr
Where π is the pi(3.14 or 22/7), and r is the radius which is half of the diameter.
Since we are given the diameter, we need to find the radius. So 1/2 of the diameter (26 x 1/2) = is 13
Now we just plug in the actual values in the formula:
a = 2πr
a = 2 x 3.14 x 13
a = <u>18.84 feet</u>
But now, we need to find how many revolutions it would take to get to 500 feet.
So we divide 500 feet by 18.84 feet;
500/18.84 = 26.53, around 27 revolutions.
Answer:
The number is 18
Step-by-step explanation:
You can write an equation to represent this. Let x represent the unknown number.
3x - 18 = 2x
Move 2x to the left side. Remember, "change the side, change the sign." Add 0 as a placeholder to the right of the equals sign.
3x - 2x - 18 = 0
Simplify like terms.
x - 18 = 0
Move -18 to the right of the equals sign.
x = 18
Now that we know x = 18, we can substitute it into the problem.
"Eighteen less than three times 18 is two times 18."
18 x 3 = 54
54 - 18 = 36
36 is, in fact, two times 18. We can check this by dividing 36 by 2.
36 ÷ 2 = 18
Answer: She started with $160.
It will take 6 weeks before she has less than half of what she originally invested.
Step-by-step explanation:
If her money is decreasing in value by 11% each week, it means that the rate at which it is decreasing is exponential.
We would apply the formula for exponential decay which is expressed as
A = P(1 - r)^t
Where
A represents the value of the investment after t weeks.
t represents the number of weeks.
P represents the initial value of the investment.
r represents rate of depreciation.
From the information given,
A = $142.40
r = 11% = 11/100 = 0.11
t = 1
Therefore
142.40 = P(1 - 0.11)^1
142.40 = P(0.89)
P = 142.4/0.89
P = 160
For her to have half of what she invested originally, then
80 = 160(0.89)^t
80/160 = (0.89)^t
0.5 = (0.89)^t
Taking log of both sides to base 10
Log 0.5 = log0.89^t = tlog0.89
- 0.3010 = - 0.051t
t = - 0.3010/- 0.051
t = 5.9
Approximately 6 weeks
I think this is what you are looking for:
=−12
a
b
=
−
12
+=4
a
+
b
=
4
(+)2=42
(
a
+
b
)
2
=
4
2
2+2+2=16
a
2
+
b
2
+
2
a
b
=
16
∴2+2=16+2×12=40
∴
a
2
+
b
2
=
16
+
2
×
12
=
40
Now, (−)2=2+2−2=40+2×12=64
(
a
−
b
)
2
=
a
2
+
b
2
−
2
a
b
=
40
+
2
×
12
=
64
∴(−)=64‾‾‾√=±8
∴
(
a
−
b
)
=
64
=
±
8
So, 2−2=(+)(−)
a
2
−
b
2
=
(
a
+
b
)
(
a
−
b
)
2−2=(4)(±8)=±32
a
2
−
b
2
=
(
4
)
(
±
8
)
=
±
32
Hope that helps and sorry if it is confusing!
