let

x = the money invested at 7%

y = the money invested at 11%

an actor invests some money at 9% and 29,000 more than three times the amount at 11% means:

y = 29,000 + 3x

the total annual interest earned form the investment is 23,990:

0.07x + 0.11y = 23990

plug y = 39,000 + 3x into the last equation

0.07x + 0.11(29,000 + 3x) = 23,990

by solving we find

x = $52,000

click here to see the step by step solution of the system equation

y = 29,000 + 3*52,000

y = $185,000

lets check, indeed

0.07*52.000 + 0.11*185,000 = 23,990

the actor invested $52,000 at 7% and $185,000 at 11%.