When I do problems involving real roots, such as x = 1, why is it always x = 1 or x = - 1?
Determine the real roots of each equation:
the real root is x = 4 or x = - 4. Why is it always +/- or how can I identify this issue?
it is because you generated a factor of the form a^2 - b^2 = (a + b)(a - b), the difference of two squares. And why not? They are just exercises, training wheels for a rigorous future math scrimages, if you mind. And multiplicity of roots often comes out handy with some other textbooks . . . .