Calculer et donner les résultats sous forme de fraction simplifier le + possible : (encore) A = 30/21 x 7/15. B= -42/25 x (-45) C= 28/48 x (-62/32) D = 14/9

A = 30/21 x 7/15
A = 210/315
A = 105 x 2 / 105 x 3
A = 2/3

B= -42/25 x (-45)
B = 1890/25
B = 5 x 378 / 5 x 5
B = 378/5

C= 28/48 x (-62/32)
C = - 1736/1536
C = 8 x - 217 / 8 x 192
C = - 217/192

D = 14/9 x -49/7 x ( -18/343)
D = - 686/63 x (- 18/343)
D = 12348/21609
D = 3087 x 4 / 3087 x 7
D = 4/7

Salut !

[tex]A= \frac{30}{21} * \frac{7}{15} \\ \\ A = \frac{2*15*1*7}{7*3*15*1} \\ \\ A = \frac{2}{3} \\ \\ \\ B = \frac{-42}{25} * (-45) \\ \\ B = \frac{-42*(-9)*5}{5*5} \\ \\ B = \frac{378}{5} [/tex]


[tex]C = \frac{28}{48} * \frac{-62}{32} \\ \\ C = \frac{7*4*(-31)*2}{2*24*8*4} \\ \\ C = \frac{-217}{192} \\ \\ \\ D = \frac{14}{9} * \frac{-49}{7}*(- \frac{18}{343}) \\ \\ D = \frac{7*2*(-1)*49*9*(-2)}{1*9*1*7*7*49} \\ \\ D = \frac{4}{7} [/tex]


J'espère t'avoir aidé(e) ! :)