10х-6-25х^2+1=28x+4
-25^2-18x-2=0
25x^2+18x+2=0
посчитаем дискриминант:он равен √31
х=(-9-√31)/25
x=(-9+√31)/25
(2-b)/b +(b-3)/3b²=(3b(2-b)+b-3)/3b²=(6b-3b²+b-3)/3b² =(7b-3b²-3)/3b²
(3c+9)/6c * 2c^4/(c+3)=(3(c+3) * 2c^4)/(6c*(c+3))=(6c^4(c+3))/(6c(c+3))=c³
(x²-y²)/6y : (x-y)²=((x-y)(x+y))/(6y(x-y)(x-y)) =(x+y)/(6y(x-y))
a^2 - (b^2 + 2bc + c^2) =
= a^2 - (b + c)^2 =
= (a - b - c)(a + b + c)
Cx-cy-dx+dy
Должно быть правильно