So when Helmholtz recognized that thought moves at a finite rate, faster than a bird but slower than sound, he missed a fundamental difference between the brain and a telegraph. In our heads, speed is not always the most important thing. Sometimes what really matters is timing.
A solution of a quadratic equation is a value of the variable that makes the equation true. Many quadratic equations. can be solved by factoring and using the zero-factor property. The Zero-Factor Property: When the product of two real numbers is 0, at least one of them is 0.
Now, if we know that there is a double zero, like in your case $-1$, that means not only is $(x - (-1))$ a factor [which, if you simplify, equals $(x + 1)$]. But actually, since $-1$ is a double zero, then $(x - (-1))^{2}$ is a factor of the polynomial. So $(x - (-1))^{2}$, which equals $(x + 1)^{2}$, is a factor. So multiply this out and get $x^{2} + 2x + 1$. Now use polynomial long division to divide this into your original polynomial to get the other factors.