Question 75521
 

Let x=amount invested at 12%

Then (2300-x)=amount invested at 10%

0.12x=interest earned on the 12% investment (for 1 year. (I=PRT))

0.10(2300-x)=interest earned on the 10% investment

So, we are told that if we add $100 to the interest on the 10% investment, it will equal the interest earned on 12% investment.

Then our equation to solve is:

0.10(2300-x)+100=0.12x  get rid of parens

230-0.10x+100=0.12x  add 0.10x to both sides

230-0.10x+0.10x+100=0.12x+0.10x  collect like terms

330=0.22x  divide both sides by 0.22

x=$1500----------------amount invested at 12%

$2300-x=$2300-$1500=$800--------------------------amount invested at 10%

CK
interest from 12% investment=1500*0.12=$180
interest from 10% investment=$800*0.10=$80
$80+$100=$180
$180=$180

Hope this helps----ptaylor