Answer:
7
Step-by-step explanation:
[tex]3 {(x + 9)}^{ \frac{3}{4} } = 24 \\ \\ {(x + 9)}^{ \frac{3}{4} } = \frac{24}{3} \\ \\ {(x + 9)}^{ \frac{3}{4} } = 8 \\ \\ {(x + 9)}^{ \frac{3}{4} } = {2}^{3} \\ \\ (x + 9) = {2}^{3 \times \frac{4}{3} } \\ \\ x + 9 = {2}^{4} \\ \\ x + 9 = 16 \\ \\ x = 16 - 9 \\ \\ x = 7[/tex]
