bonjour
A = ( 1 + 2/5 ) ( 1 - 7/2 )
= ( 5/5 + 2/5 ) ( 2/2 - 7 /2)
= 7/5 * - 5/2
= - 35/10
= - 7 /2
B = ( 2 - 1 /3) : ( 2/5 - 1 )
= ( 6/3 - 1/3) : ( 2/5 - 5/5 )
= 5/3 : - 3 /5
= 5/3 * - 5/3
= - 25 /9
C = - 6 : 18/5
= - 6 * 5/18
= - 30/18
= - 5/3
D = 3 - 2/3 x 3 / 6
= 3 - 6/18
= 3 - 1/3
= 3/3 - 1/3 = 2/3
E = ( 3 - 2/3) * 6 / 3
= ( 9/3 - 2 /3 ) * 6/3
= 7/3 * 6/3
= 42/9
= 14/3
F = 1 - 2 * - 1 /4
= 1 + 2/4
= 4/4 + 2/4
= 6 /4 = 3 /2
