А²+ab= a(a+b)
2xy-x³= x(2y-x²)
x²y²+y^4= y²(x²+y²)
U+v=4
3u-5v=20
u=4-v
3(4-v)-5v=20,12-3v-5v=20,12-8v=20,8v=12-20,8v=-8,v=-1
u=4-v
v=-1
u=4-(-1)=4+1=5
v=-1
/u,v/=/5,-1/
========
Обратные корни:
х1 = -1/3
х2 = -1/5
По теореме Виета:
x1 + x2 = -b
x1*x2 = c
x1 + x2 = -1/3 - 1/5 = -5/15 - 3/15 = -8/15
b = 8/15
x1*x2 = -1/3 * (-1/5) = 1/15