simplify and show me how

7t^4*7t^4

This can be simplified using the product of powers rule, which states that when you multiply two powers with the same base, you can add the exponents:

7t^4 * 7t^4 = 7 * 7 * t^4 * t^4
= 49t^(4+4)
= 49t^8

Therefore, 7t^4 * 7t^4 simplifies to 49t^8.