____________________________________________________________________ (это проверка)
x^2 - 10x +25= 5x^2 - 4x^2 - 2x +2x +1
x^2 - 10x +25= x^2 +1
-10x+25=1
-10x=-24
x=24/10
x=12/5
x=2,4
____________________________________________________________________
(это проверка)
x^2 - 10x +25= 5x^2 - 4x^2 - 2x +2x +1
x^2 - 10x +25= x^2 +1
-10x+25=1
-10x=-24
x=24/10
x=12/5
x=2,4