please help struggling with Math 115 Word problem

Question

Jason just retired, and has $710,000 to invest. A very safe Certificate of Deposit (CD) account pays 1%, while a riskier bond fund pays 7.5% in interest. Jason figures he needs $14,000 a year in interest to live on. How much should he invest in each account to make enough interest while minimizing his risk?

Answer 1

1% = 0.01 and 7.5% = 0.075

X+Y = 710000

0.01X + 0.075Y = 14000

Solves first equation for y and multiplies second equation by 1000 to clear away the decimals:

Y = 710000 - x

10X + 75Y = 14000000

10X + 75(710000 - x) = 14000000

10X + 53250000 - 75x = 14000000

-65x = -39250000

x = 603846.16

y = 106153.85