For the first equation:
y = (x + 5)(x + 1)
apply distribution property:
y = (x + 5)(x) + (x + 5)(1)
y = x·x + 5·x + x·1 + 5·1
y = x² + 5x + x + 5
y = x² + 6x + 5
For the second equation:
y = (x + 3)² - 4
use the fact that (a + b)² = a² + 2ab + b², for the term (x + 3)², then, you have:
y = x² + 2·x·3 + 3² - 4
y = x² + 6x + 9 - 4
y = x² + 6x + 5
The third equation is already in the convenient form.
Then, you can notice that all three equations are the same equations.