" alt="(3x+x^2) ^2-x^2 (x-5) (x+5) -2x (8-3x^2) = \\ = 9 {x}^{2} + 6 {x}^{3} + {x}^{4} - {x}^{2} ({x}^{2} - 25) - 16x + 6 {x}^{3} = \\ = 9 {x}^{2} + 6 {x}^{3} + {x}^{4} - {x}^{4} + 25 {x}^{2} - 16x + 6 {x}^{3} = \\ = 12 {x}^{3} + 34 {x}^{2} - 16x
" align="absmiddle" class="latex-formula">