[tex]-5t^2+20t+1,6 = 0 \\ -5(t^2-4t-0,32) =0 \\ t^2-4t-0,32 =0 \\ (t-2)^2 = t^2 -4t + 4 \\ (t-2)^2 - \frac{432}{100} =0 \\ (t-2)^2 - (\frac{12\sqrt{3}}{10})^2 =0 \\ (t-2- \frac{12\sqrt{3}}{10})(t-2+ \frac{12\sqrt{3}}{10}) =0 \\ (t- \frac{10+6\sqrt{3}}{5})(t- \frac{10-6\sqrt{3}}{5}) =0\\ donc\,2\,solutions: t=\frac{10+6\sqrt{3}}{5}\,ou\,\frac{10-6\sqrt{3}}{5}[/tex]
En espérant t'avoir aidé.
