Question

розвяжіть рівняння (x-3)2-2x2+18=0

Answer 1

$(x-3)^{2} -2x^{2}+18=0\\\\x^{2}-6x+9-2x^{2}+18=0\\\\-x^{2} -6x+27=0\\\\x^{2}+6x-27=0\\\\D=6^{2}-4*(-27)=36+108=144=12^{2}\\\\x_{1}=\frac{-6-12}{2} =\frac{-18}{2}=-9\\\\x_{2}=\frac{-6+12}{2}=\frac{6}{2}=3\\\\Otvet:\boxed{x_{1}= -9 \ ;\ x_{2} = 3}$