Final answer:
After substituting 7 for x in the expression y = x² - 1/x² - 1, and simplifying both the numerator and the denominator, we find that y equals 1 when x is 7.
Step-by-step explanation:
The expression given is y = x² - 1/x² - 1. To determine the value of y when x is 7, we will substitute 7 for x in the expression.
First, calculate the numerator:
x² - 1 = (7²) - 1 = 49 - 1 = 48.
Then, calculate the denominator:
x² - 1 = (7²) - 1 = 49 - 1 = 48.
Finally, divide the numerator by the denominator:
y = 48 / 48.
As a result, y equals 1 when x is 7.