\frac{x\cdot2x-x^2-121}{x^2}=0\\(x-11)(x+11)=0\\x=-11\\y(-11)=\frac{121+121}{-11}=-22\\y(-1)=\frac{1+121}{-1}=-122\\y(-20)=\frac{400+121}{-20}=-26,05\\y_{max}=-22" alt="y=\frac{x^2+121}{x}\\\\y'=\frac{x\cdot2x-x^2}{x}\\y'=0<=>\frac{x\cdot2x-x^2-121}{x^2}=0\\(x-11)(x+11)=0\\x=-11\\y(-11)=\frac{121+121}{-11}=-22\\y(-1)=\frac{1+121}{-1}=-122\\y(-20)=\frac{400+121}{-20}=-26,05\\y_{max}=-22" align="absmiddle" class="latex-formula">