x^2+4x-5x^2-1
You have to look for commmon terms
4x^2+4x-1
And you have a cuadratic equation
x2+4x-5x2-1
= -4x2 + 4x - 1
= \(-4(x^{2}-x+\frac{1}{4})\)
= \(-4(x - \frac{1}{2})(x - \frac{1}{2})\)
= \(-4(x - \frac{1}{2})^{2}\)
