# SOLUTION: Michael has \$12,500 to invest. He invests part in an account which earns 4.2% annual interest and the rest in an account which earns 6.2% annual interest. He earns \$669.50 in inter

Algebra ->  Algebra  -> Percentage-and-ratio-word-problems -> SOLUTION: Michael has \$12,500 to invest. He invests part in an account which earns 4.2% annual interest and the rest in an account which earns 6.2% annual interest. He earns \$669.50 in inter      Log On

 Ad: Algebrator™ solves your algebra problems and provides step-by-step explanations! Ad: Algebra Solved!™: algebra software solves algebra homework problems with step-by-step help!

 Word Problems: Problems on percentages, ratios, and fractions Solvers Lessons Answers archive Quiz In Depth

 Click here to see ALL problems on Percentage-and-ratio-word-problems Question 399228: Michael has \$12,500 to invest. He invests part in an account which earns 4.2% annual interest and the rest in an account which earns 6.2% annual interest. He earns \$669.50 in interest at the end of the year. How much was invested at each rate?Found 2 solutions by stanbon, robertb:Answer by stanbon(57347)   (Show Source): You can put this solution on YOUR website!Michael has \$12,500 to invest. He invests part in an account which earns 4.2% annual interest and the rest in an account which earns 6.2% annual interest. He earns \$669.50 in interest at the end of the year. How much was invested at each rate? ----- Equations: Quantity Eq.:: x + y = 12,500 Interest Eq.::0.042x + 0.062y = 669.50 ---------------------- Multiply thru Quantity by 42. Multiply thru Interest by 1000. ---------------------- 42x + 42y = 42*12,500 42x + 62y = 669500 ------------------------------ Subtract 1st from 2nd and solve for "y": 20y = 144500 y = \$7225 (amt. invested at 6.2% ------ Solve for "x": x+ y = 12,500 x + 7225 = 12,500 x = \$5275 (amt. invested at 4.2%) ================ Cheers, Stan H. Answer by robertb(4012)   (Show Source): You can put this solution on YOUR website!0.042x + 0.062(12,500 - x) = 669.50 ==> 0.042x + 775 - 0.062x = 669.50 ==> -0.02x = -105.5 ==> x = \$5,275, the amount invested in 4.2% and 12,500 - x = \$7,225, the amount invested in 6.2%.