Question 13356
Let x = amount invested at 10%
30000 - x = amount invested at 5%


.10 x + .05(30000 - x) = 2300
.10x + 1500 - .05x = 2300
.05x + 1500 = 2300
.05x = 800
{{{x = 800/.05 = 80000/5 = 16000}}} at 10%
{{{30000 - 16000 = 14000 }}} at 5%


Check:
.10($16000) + .05($14000)
$1600 + $700 = $2300


R^2 at SCC