To simplify the expression \( \frac{x^{675}}{x^{453}} \), we can apply the properties of exponents. Specifically, we can use the rule:
\[ \frac{x^a}{x^b} = x^{a-b} \]
In this case, \( a = 675 \) and \( b = 453 \). Therefore, we calculate:
\[ 675 - 453 = 222 \]
So, we can rewrite the expression as:
\[ \frac{x^{675}}{x^{453}} = x^{675 - 453} = x^{222} \]
Thus, the simplified form of \( \frac{x^{675}}{x^{453}} \) is:
\[ \boxed{x^{222}} \]