Bjr, pourriez vous m aider pour mon dm de maths, svp, un grand merci. Ex 1 et 2.

bonjour

A = ( 3/4 + 1/3 ) : ( 7/3 - 2 )

A = ( 9/12 + 4/12) : ( 7/3 - 6/3)

A = 13/12 : 1/3

A = 13/12 x 3 = 39/12

A = 13/ 4

B  = ( 3 a - 2 ) ( 4 - 2 a)  

B = 12 a - 6 a² - 8 + 4 a

B = - 6 a² + 16 a - 8

pour a = 4/3

B = - 6 ( 4/3)² + 16 ( 4/3) - 8

B = - 6 x 16/9 + 64/3 - 8

B = - 96/9 + 64/3 - 8

B = - 96/9 + 288/9 - 72/9

B = 120/9 = 40/3

Bonsoir,

1)

A = (3/4 + 1/3) : (7/3 - 2)

A = [(3 x 3) /(4 x 3) + (1 x 4) / (3 x 4)] : [7/3 - (2 x 3) / (1 x 3)]

A = (9/12 + 4/12) : (7/3 - 6/3)

A = 13/12 : 1/3

A = 13/12 x 3

A = 39/12

A = (3 x 13) / (3 x 4)

A = 13/4

2)

B = (3a - 2) (4 - 2a)

B = 12a - 6a² - 8 + 4a

B = - 6a² + 12a + 4a - 8

B = - 6a² + 16a - 8.

Pour a = 4/3

B = - 6 * 4/3² + 16 * 4/3 - 8

B = - 6 * 4²/3² + 64/3 - 8

B = - 6 * 16/9 + 64/3 - 8

B = - 96/9 + (64 x 3) / (3 x 3) - (8 x 3) / (3 x 3)

B = - 96/9 + 192/9 - 24/9

B = 72/9

B = (9 x 8) / (9 x 1)

B = 8