To express the number 9 as a fraction with 7 in the denominator, you can represent 9 as a fraction by placing it over 1, giving you 9/1. From there, you want to create a fraction that has 7 as its denominator.
To do this, you can multiply both the numerator and denominator of 9/1 by 7. This keeps the fraction equivalent to 9 while adjusting the denominator:
(9 * 7) / (1 * 7) = 63/7
Thus, 9 can be written as the fraction 63/7.