bonjour besoin aide svp​

Bonjour,

a)

14/6 * 3/3 = 42/18

3/9 * 2/2 =6/18  

(42/18 -6/18) * -3/4

= 36/18 *3/4

= 108/72  =54/36 = 27/18 = 9/6 = 3/2

b)

(11/15 -3/25) /9/35

11/15 * 5/5 = 55/75

3/25 *3/3 = 9/75

55/75 - 9/75 =46/75

46/75  / 9/35

= 46/75 * 35/9

= 28/15