# Can anyone help me with my math extra credit? Using the simple interest formula I=prt

• October 11th 2009, 12:16 PM
fzwarrior
Can anyone help me with my math extra credit? Using the simple interest formula I=prt
Tom made \$190.00 interest after investing \$5,500 for one year. part was invested @ 5.5% with the rest @ 3%. Using a Mixture Equation calculate the amount invested at each rate.
• October 11th 2009, 12:41 PM
skeeter
Quote:

Originally Posted by fzwarrior
Tom made \$190.00 interest after investing \$5,500 for one year. part was invested @ 5.5% with the rest @ 3%. Using a Mixture Equation calculate the amount invested at each rate.

let $x$ = interest earned

$y$ = amount of investment

$I = prt$

$x = y(.055)(1)$

$(190-x) = (5500-y)(.03)(1)$

solve the system for $y$ and $(5500 - y)$