bonjour
RU = -5/2 ST
⇒
[tex]\left \{ {{xu-xr=-\frac{5}{2}( xt-xs)} \atop {yu-yr=-\frac{5}{2}(yt-ys)}} \right. \\\\\left \{ {{xu=-\frac{5}{2}( xt-xs)+xr} \atop {yu=-\frac{5}{2}(yt-ys)+yr}} \right. \\\\\\\left \{ {{xu=-\frac{5}{2}( -1-7)-2} \atop {yu=-\frac{5}{2}(6-3)+6}} \right. \\\\\\\\\\\left \{ {{xu=18} \atop {yu=-1,5}} \right. \\\\\\\\[/tex]
donc U(18;-1,5)
