Bonjour,

A = 3/5 - 1/5 * 7/3

A = 3/5 - 7/15

A = 9/15 - 7/15

A = 2/15

B = (2/9 + 1/6)/(2 - 7/3)

B = (12/54 + 9/54)/(6/3 - 7/3)

B = (21/54)/(-1/3)

B = (21/54)/(-18/54)

B = -7/6