$y=-\frac{1}{10}\,x(x-4)(x+5)$

$y=-\frac{1}{10}\,x(x-4)(x+5)^{2}$

$y=-\frac{1}{10}\,x(x-5)(x+4)$

$y=-\frac{1}{10}\,x(x-5)^{2}(x+4)$