I will give brainliest please help me asap! Simplify the expression. Make sure you have all positive exponents.

Answer:
[tex]{x}^{21} [/tex]
Step-by-step explanation:
x^7×3
x^21
Answer:
x^21.
Step-by-step explanation:
=(x^7)^3 (first multiply the powers like 3*7 it gives result 21)
=x^21 ( so the power of x becomes 21)