Hi there!
y = x² - 5x - 6
Rewrite into factored form by finding two numbers that sum up to -5 and multiply into -6. We can use the numbers -6 and 1:
y = (x - 6)(x + 1) is the equation in factored form.
There are zeroes at:
0 = x - 6
x = 6
0 = x + 1
x = -1
Find the x-value exactly half-way between the two zeroes to find the axis of symmetry:
(-1 + 6) / 2 = 5 / 2 = 2.5
Therefore, the equation for the line of symmetry is:
x = 2.5