The fraction:
$$\frac{y^2-x^2}{x-y}$$
should simplify to the answer:
$$-(x+y)$$
but the best I could do was expand it to:
$$\frac{(y+x)(y-x)}{x-y}$$
What's next step?
The fraction:
$$\frac{y^2-x^2}{x-y}$$
should simplify to the answer:
$$-(x+y)$$
but the best I could do was expand it to:
$$\frac{(y+x)(y-x)}{x-y}$$
What's next step?
For $x \neq y$, $$\frac{(y+x)(y-x)}{x-y} = \frac{(y+x)(y-x)}{-(y-x)}$$
$$ = -(y+x)$$ $$ = -(x+y)$$