3x^2-x-85+11x^2=0
14x^2-x-85=0
D=1-4*14*(-85)=4761
x1,2=1-+69/6
x1=70/6=35/3=11 2/3; x2=-68/6=-34/3=11 1/3
(x+5)^2=(x-3)^2
x^2+10x+25=x^2-6x+9
16x=-16
x=1
2y - xy² + 6xy - 3x²y² = (2y - xy²) + (6xy - 3x²y²) = y(2-xy) + 3xy(2-xy) =
= (2-ху)(у+3ху)
У меня 2 варианта
( не очень понятно условие задания)
![3 \sqrt{x} -12=0 \\ 3 \sqrt{x} =12 \\ \sqrt{x} =4 \\ x=4 ^{2} \\ x=16 \\ \\ 3 \sqrt{x-12} =0 \\ \sqrt{x-12} =0 \\ x-12=0 \\ x=12](https://tex.z-dn.net/?f=3+%5Csqrt%7Bx%7D+-12%3D0+%5C%5C+3+%5Csqrt%7Bx%7D+%3D12+%5C%5C++%5Csqrt%7Bx%7D+%3D4+%5C%5C+x%3D4+%5E%7B2%7D++%5C%5C+x%3D16+%5C%5C++%5C%5C+3+%5Csqrt%7Bx-12%7D+%3D0+%5C%5C++%5Csqrt%7Bx-12%7D+%3D0+%5C%5C+x-12%3D0+%5C%5C+x%3D12)