WILL GIVE BRANLIEST! pls help thank u sm!! :-) u are all amazing

Answer:
C
Step-by-step explanation:
Given
3[tex](x+9)^{\frac{3}{4} }[/tex] = 24 ( divide both sides by 3 )
[tex](x+9)^{\frac{3}{4} }[/tex] = 8
Raise both sides to the power of [tex]\frac{4}{3}[/tex]
x + 9 = [tex]8^{\frac{4}{3} }[/tex] = [tex](\sqrt[3]{8}) ^{4}[/tex] = [tex]2^{4}[/tex] = 16 ( subtract 9 from both sides )
x = 7 → C