/ signifie divisé par
* signifie multiplié par ou fois
A = 1/5 * -4/3 + 7/2
A = (1*-4)/(5*3) + 7/2
A = -4/15 + 7/2
A = (-4*2)/(15*2) + (7*15)/(2*15)
A = -8/30 + 105/30
A = (-8+105) / 30
A = 97/30
B = 7/3 + 3/2 * -10/21
B = 7/3 -30/42 or 42 = 3*14
B = 7*14/3*14 -30/42
B = (98-30)/42
B = 68/42
B = 34/21
C = 6/5 - (- 1/9) * (- 3/4)
C = 6/5 - (3/9*4)
C = 6/5 - 1/(3*4)
C = 6/5 - 1/12
C = (6*12) / (5*12) - (1*5) / (12*5)
C = (72-5) / 60
C = 67/60