Evaluate please I need helppppp!!!!!!!

Answer:
400
Step-by-step explanation:
[tex] \bigg( \frac{5}{6} a \bigg)^{2} \\ \\ = \bigg( \frac{5}{\cancel 6} \times \cancel {24} \bigg)^{2} \\ \\ = \bigg( 5 \times 4 \bigg)^{2} \\ \\ = {(20)}^{2} \\ \\ = 400[/tex]