what is the amount of each loan

Question

Bobs two student loans total to $9000. One loan is 4.5% simple intreste adn the other is at 5.5% simple interest. At the end of one year, Bob owes $447 in interest. What was the amount of each loan?

Answer 1

x = amount of loan at 4.5%

9000 - x = amount of loan at 5.5%

 

0.045x + 0.055(9000 - x) = 447

 

Solve for x.

 

x(0.045 - 0.055) = 447 - 0.055(9000)

 

-0.01x = -48

 

x = 48/0.01 = 4800

9000 - x = 9000 - 4800 = 4200

 

He borrowed $4800 at 4.5% and $4200 at 5.5%.