Complete question :
Martin deposits $200 in a savings account that earns 5% annual interest. four years later, cary deposits $200 in an account earning the same interest. let m represent the balance in martins account and let c represent the amount of money in carys account. choose the pair of expressions that describe the accounts y years after martin opened his account. martin: 200(1.05)y cary: 200(1.05)y+4 martin: 200(1.05)y+4 cary: 200(1.05)y4 martin: 200(0.05)y cary: 200(0.05)y4 martin: 200(1.05)y cary: 200(1.05)y4 choose the equation that relates the balances in the accounts y years after martin opened his account. c = m(1.05)4y m = c(1.05)4y c = 1.22m m = 1.22c
Answer:
m = m = 200(1.05)^y+4
c = m = 200(1.05)^y
m = 1.22c
Step-by-step explanation:
The future value can be represented as :
Future value, F = P(1 + r)^n
r = interest rate = 5% = 0.05 , n = number of years ;
For Martin :
m = 200(1 + 0.05)^n
For cyan :
c = 200(1 + 0.05)^n
y years after Martin
Cyan opened 4 years after Martin :
Representing in terms of y
Cyan = y ; Martin = y +4
m = m = 200(1.05)^y+4
c = m = 200(1.05)^y
From. Indices :
(1.05)^y+4 = 1.05^y * 1.05^4
Hence,
m = 200 * 1.05^y * 1.05^4
c = 200 * 1.05)^y
Hence,
m = c * 1.05^4
m = c * 1.2155
m = c * 1.22
m = 1.22c