Answer:
X= 75, Y=30 there you go!
Step-by-step explanation:
Try YouTube there should be videos on how to do it .
The required equation is y = 10000(1.0.25)^2x. The value of Christina’s investment after 20 years is $30,773.14
Compound interest
The interest accrued on a sum of money is known as interest. The formula for calculating the compound interest is expressed as:
y = y0(1+r/n)^nx
where
x is the time taken
r is the rate in decimal
n is the compounding time
Given the following
x = 20 years
n 2(semi annually)
r = 5.7% = 0.057
Substitute
y = 10000(1+0.057/2)^2(20)
y = 10,000(1 + 0.0285)^40
y = 10000(1.0285)^40
y = 30,773.14
Hence the value of Christina’s investment after 20 years is $30,773.14
Learn more on compound interest here: brainly.com/question/24924853
Answer:
r = 4/5
Step-by-step explanation:
Formula
Sum of an infinite geometric series = a / (1 - r)
Givens
Sum = 5*a
a = a
r = ?
Solution
5a = a/(1 - r) Divide both sides by a
5a/a = a / (a * (1 - r) The a's on the right cancel
5 = 1 / (1 - r) Multiply both sides by 1 - r
5*(1 - r) = 1*(1 - r)/(1 - r) The 1 - r s on the right cancel
5*(1 - r) = 1 Remove the brackets.
5 - 5r = 1 Subtract 5 from both sides
5-5 - 5r = 1 - 5 Combine
-5r = - 4 Divide by - 5
r = 4/5