Question

СРОЧНО!!!!!!!! Розв’яжіть рівняння: y 3 + 18y 2+ 81y= 0.

Answer 1

$\displaystyle\bf\\y^{3} +18y^{2}+81y=0\\\\y\cdot(y^{2}+18y+81)=0\\\\y\cdot(y+9)^{2} =0\\\\\\\left[\begin{array}{ccc}y=0\\(y+9)^{2}=0 \end{array}\right\\\\\\\left[\begin{array}{ccc}y=0\\y+9=0\end{array}\right \\\\\\\left[\begin{array}{ccc}y_{1}=0 \\y_{2}=-9 \end{array}\right\\\\\\Otvet \ : \ 0 \ ; \ -9$