Get reliable answers to your questions at Westonci.ca, where our knowledgeable community is always ready to help. Ask your questions and receive detailed answers from professionals with extensive experience in various fields. Get immediate and reliable solutions to your questions from a community of experienced professionals on our platform.

1. Dylan invested $47,000 in an account paying an interest rate of 4% compounded annually. Assuming no deposits or withdrawals are made, how long would it take, to the nearest tenth of a year, for the value of the account to reach $79,200?

2. x^2 + y^2 = 153 and y = -4x. If (x, y) is a solution to the system of equations above, what is the value of y^3?


Sagot :

zcathy

Answer:

(1) 13.0 years

(2) [tex]y^{3} =[/tex] {-1728, 1728}

Step-by-step explanation:

(1)

Compound annually:

[tex]Pe^{rt}[/tex] = A

(47000)[tex]e^{(0.04)(t)}[/tex] = 79200

[tex]e^{(0.04)(t)}[/tex] = [tex]\frac{79200}{47000}[/tex]

ln([tex]e^{(0.04)(t)}[/tex]) = ln([tex]\frac{79200}{47000}[/tex])

ln and e cancel out.

(0.04)(t) = ln([tex]\frac{79200}{47000}[/tex])

t = [tex]\frac{ln(\frac{79200}{47000})}{0.04}[/tex]

t = 13.0 years

(2)

[tex]x^{2} +y^{2} = 153\\y = -4x[/tex]

Substitute y with -4x.

[tex]x^{2} + (-4x)^{2} = 153[/tex]

Solve for x.

x = {-3, 3}

Plug in x values into any equation to find y.

y = -4(-3) and y = -4(3)

y = {-12, 12}

[tex]y^{3}[/tex] = [tex]-12^{3}[/tex] = -1728

[tex]y^{3}[/tex] = [tex]12^{3}[/tex] = 1728

Answer:

13.3    

Step-by-step explanation:

I got it right