Question 144992
Let x be the amount invested at 7%. Then (15000-x) is the amount at 9%

{{{0.07x + 0.09(15000-x) = 1230}}}
{{{-0.02x + 1350 = 1230 }}}
{{{-0.02 x = -120 }}}
{{{x = 6000}}}

9000 at 9%
6000 at 7%