Помогите плиз с 8,9,10)

8. 1/4 х^2–0,09=0 1/4 х^2=0,09 х^2=(9•4)/100=0,36 х1=0,6; х2=–0,6 9. 16 ---- х^2 – (7у–0,2х)^2 = 25 4 1 4 1 = ( --- х –7у + --- х)( --- х + 7у – --- х) = 5 5 5 5 = (х–7у)(3/5х+7у) 10. 36m^2–1–(6m–1)^2=–8 (6m–1)(6m+1)–(6m–1)^2=–8 (6m–1)(6m+1–6m+1)=–8 2(6m–1)=–8 |:2 6m–1=–4 6m=–3 m=–1/2