Answer:
La ecuación genérica para un círculo centrado en el punto (a, b), de radio R, es:
(x - a)^2 + (x - b)^2 = R^2
Entonces si miramos a nuestra ecuación:
(x + 2)^2 + (y - 3)^2 = 121
Tendremos el centro en:
(-2, 3)
el radio está dado por:
R^2 = 121
R = √121 = 11
La gráfica de esta circunferencia se puede ver en la imagen de abajo.
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
Answer:
a) 22:53
b)213 min
Step-by-step explanation:
c) 10 17 + 4 = 14 17
she has 2 minutes to spare
Answer:
≈ 30.63 cm²
Step-by-step explanation:
The shaded area is calculated by subtracting the area of the inner circle from the area of the outer circle.
outer circle has radius = 8 ÷ 2 = 4 and inner circle has radius = 5 ÷ 2 = 2.5
shaded area = πr₁² - πr₂² (r₁ is outer and r₂ is inner )
A = π (4² - 2.5²)
= π(16 - 6.25) = 9.75π ≈ 30.63 cm²
