Hello, and thank you for posting your question here on brainly..
Look at the work provided below.
s = 4
t = 8
2 * 4 * 8^2 - 4^2
Do exponents first.
8 * 8 = 64
4 * 4 = 16
2 * 4 * 64 - 16
8 * 64 - 16
512 - 16
496
496 is your final answer.
Hope this helps! ☺♥