1)4х(3у+7)
2)12а(3bкв-аb)
3)-6b(5yкв+b)
4)-6b(5yкв+b)
5)x(9-11)
17xy+34 17(xy + 2) 17
------------- = ---------------- = --------- = 1
17(xy+2) 17(xy + 2) 17
Подставим вмести х корень х₁ = 1
1-5+5+А = 0
А = -1
х³ - 5х² + 5х - 1 = 0
(х³-1) - 5х(х-1) = 0
(х-1)(х²+х+1 - 5х) = 0
х²-4х+1 = 0
(х - (2 + √3))(х - (2-√3)) = 0
х₂ = 2+√3
х₃ = 2 - √3