General simplification
[src]
$$- x^{2} - 7 x y - y^{2}$$
/ / ___\\ / / ___\\
| y*\-7 + 3*\/ 5 /| | y*\7 + 3*\/ 5 /|
|x - ----------------|*|x + ---------------|
\ 2 / \ 2 /
$$\left(x - \frac{y \left(-7 + 3 \sqrt{5}\right)}{2}\right) \left(x + \frac{y \left(3 \sqrt{5} + 7\right)}{2}\right)$$
(x - y*(-7 + 3*sqrt(5))/2)*(x + y*(7 + 3*sqrt(5))/2)
The perfect square
Let's highlight the perfect square of the square three-member
$$- x^{2} + \left(- x 7 y - y^{2}\right)$$
Let us write down the identical expression
$$- x^{2} + \left(- x 7 y - y^{2}\right) = \frac{45 y^{2}}{4} + \left(- x^{2} - 7 x y - \frac{49 y^{2}}{4}\right)$$
or
$$- x^{2} + \left(- x 7 y - y^{2}\right) = \frac{45 y^{2}}{4} - \left(x + \frac{7 y}{2}\right)^{2}$$
Rational denominator
[src]
$$- x^{2} - 7 x y - y^{2}$$
Assemble expression
[src]
$$- x^{2} - 7 x y - y^{2}$$
$$- x^{2} - 7 x y - y^{2}$$
$$- x^{2} - 7 x y - y^{2}$$
$$- x^{2} - 7 x y - y^{2}$$
$$- x^{2} - 7 x y - y^{2}$$
Combining rational expressions
[src]
$$- x^{2} + y \left(- 7 x - y\right)$$