Question

determine the value of y, if x is -7.
y = x² - 9

Explanation:

Step1: Substitute \( x = -7 \) into the equation

We replace \( x \) with \( -7 \) in the equation \( y = x^2 - 9 \), so we get \( y = (-7)^2 - 9 \).

Step2: Calculate \( (-7)^2 \)

\( (-7)^2 = 49 \) because squaring a negative number gives a positive result.

Step3: Subtract 9 from the result

Now we have \( y = 49 - 9 \), and \( 49 - 9 = 40 \).

Answer:

\( 40 \)