bonjour, pouvez vous m'aider ? Merci​

Bonsoir

Calculer et simplifier :

A = 81/70 x 25/18

A = (9 x 9 x 5 x 5)/(7 x 2 x 5 x 2 x 9)

A = (45 x 45)/(45 x 28)

A = 45/28

B = 98/25 x 5/6

B = (2 x 49 x 5)/(5 x 5 x 2 x 3)

B = (10 x 49)/(10 x 15)

B = 49/15

2) simplifier :

315/270

= (5 x 7 x 9)/(5 x 6 x 9)

= (45 x 7)/(45 x 6)

= 7/6

(2021 + 2021)/(2021 + 2021 + 2021 + 2021 + 2021 + 2021)

= (2 x 2021)/(6 x 2021)

= 2/6

= 2/(2 x 3)

= 1/3

Trouver x tel que 2/3 = x/5 :

x = (2 * 5)/3

x = 10/3