Math help ease and thank you!

Question

A total of $12,000 is invested in two bonds that pays 8.5% and 10% simple interest. The annual interest is $1140. How much is invested in each bond?

Answer 1

Amount = Principal x Rate x Time       $1140 = [.085P + .10(12000 - P)] x 1

 

$1140 = (.085P +1200 -.10P) x 1       $1140 = -.015P + 1200  Subtract 1200 from both sides.

 

-$60 = -.015P  Divide both sides by -.015.     P = $4000 at 8.5%        12000 - 4000 = $8000 at 10%

Answer 2

Let x = amount invested at 8.5%

Then, 12000 - x = amount invested at 10%

 

0.085x + 0.10(12000 - x) = 1140

 

0.085x + 1200 - 0.10x = 1140

 

-0.015x = -60

 

          x = $4000

 

Invest $4000 at 8.5% and $8000 at 10%.