• -3/4 et 5/12 :
(-3 × 3) / (4 × 3) = [tex]-\frac{9}{12}[/tex]
• 6/15 et 4/3 :
(4 × 5) / (3 × 5) = [tex]\frac{20}{15}[/tex]
• -7/4 et 5/3 :
(-7 × 3) / (4 × 3) = [tex]-\frac{21}{12}[/tex] et (5 × 4) / (3 × 4) = [tex]\frac{20}{12}[/tex]
• 13/(-9) et 11/6 :
(13 × 6) / (-9 × 6) = [tex]-\frac{78}{54}[/tex] et (11 × (-9)) / (6 × (-9)) = [tex]\frac{99}{54}[/tex]
• -8/7 et -4/3 :
(-8 × 3) / ( 7 × 3) = [tex]-\frac{24}{21}[/tex] et (-4 × 7) / (3 × 7) = [tex]-\frac{28}{21}[/tex]
