$6300 is invested, part of it at 12% and part of it at 9%. for a certain year, the total yield is $nbsp 660.00. how much was invested at each rate?

$3,100 was invested at 12% and $3,200 at 9%

Step-by-step explanation:

Let x = the amount invested at 12% and y =  the amount invested at 9%

As you know 12% = 0.12 and 9% = 0.09

Given:

$6300 is invested, part of it at 12% and part of it at 9%:   x + y = 6300

The total yield is $660.00:   0.12x + 0.09y = 660

Now you have 2 equations:

x + y = 6300  > x = 6300 - y

0.12x + 0.09y = 660

Substitute x = 6300 - y  into 0.12x + 0.09y = 660 to find y

0.12(6300 - y )+ 0.09y = 660

756 - 0.12y + 0.09y = 660

                    -0.03y = -96

                             y = 3,200

                             x = 6,300 - 3,200

                             x = 3,100

$3,100 was invested at 12% and $3,200 at 9%

Hope that helps

idk

step-by-step explanation:

step-by-step explanation: