bonjour pouvez m aider svp.calculer et donner le resultat sous la forme d une fraction irreductible. A= 7/10plus 4/15 B = 7/20 :15/2 C = 1/9-15/9x1/6 D=3-2/3

bjr

A= 7/10 plus 4/15

= 7/10 + 4/15

= 7x3 / 10x3 + 4x2 / 15x2 = 21/30 + 8/30 = 29/30

B = 7/20 :15/2

=7/20 x 2/15 = 7x2 / 20x15 = 7x2 / 2x10x15 = 7/150

C = 1/9 - 15/9 x 1/6

= 1/9 - 15x1/9x6 = 1/9 - 5x3 / 3x3x6 = 1/9 - 5/18 = 2/18 - 5/18 = -3/18 = -1/6

D=3-2/3 divise par 4/3x7

D = (9/3 - 2/3) / (4/21) = 7/3 x 21/4 = 7x21 / 3x4 = 7x7x3 / 3x4 = 49/4

bonjour

A = 7/10 + 4/15

= 21/30 + 8/30

= 29/30

B = 7/20 : 15/2

= 7/20 x 2/15

= 14/300

=  7/150

C = 1/9 - 15/9 * 1/6

= 1/9 - 15/54

= 6/54 - 15/54

= - 9/54

=  - 1/6

D = 3- 3/2 : 4/3 * 7

= 3 - 3 /2 : 28/3

= 3 - 3/2 * 3/28

= 3 - 9/56

= 168/56 - 9/56

= 159/56