How do you solve by completing the square #a^2 -6a-5=0#?
When we want to make a square out of a quadratic polynomial, we need to look at the b-coefficient of the polynomial (assuming
We know that
Therefore our "a" is just going to be a, and b is going to be some number for which :
So our square is going to be
Luckily, we are free to add a zero to the equation anytime we want. Like this :
Now we can square the equation, watch out for the plus/minus signs :
And we are finished.