simplify (s3t-4)2

(s3t - 4)2 = (s3t - 4)(s3t - 4)
= s3t * s3t - 4s3t - 4s3t + 16
= s6t^2 - 8s3t + 16

Therefore, the simplified expression is s6t^2 - 8s3t + 16.