Question

A total of $7000 is invested in three accounts. Some was invested at 6%, some at 8%, and the rest at 9%. find the amount invested at each rate if the total interest for one year was $555 and the amount invested at 8% was three times the amount invested at 9%. (assume simple interest). show what each variable stands for, show each equation, show how you solved it and indicate the solution.

Answer 1

555 = .09 x + .08 (3x) + .06 (7000 - 4x)