8. (2023•山西模拟)已知sinα−cosα=15,α∈(−π2,π2)\sin \alpha -\cos \alpha =\frac{1}{5},\alpha \in (-\frac{\pi }{2},\frac{\pi }{2})sinα−cosα=51,α∈(−2π,2π),则sinαcosαsinα+cosα=(\frac{\sin \alpha \cos \alpha }{\sin \alpha +\cos \alpha }=(sinα+cosαsinαcosα=( )))