calculer en écrivant les 3 expressions suivantes X=7 (au carré2) - 4 × 6 × 10 X =

Bonsoir , 
X = 7² - 4 × 6 × 10 
X = 49 - 240
X = - 191

Y = 3/4 × 5/3 - 1/6
Y = 15/12 - 1/6
Y = 15/12 - 6/12
Y = 9/12
Y = 3/4

Z = ( 3/4 - 5/6 ) ÷ ( 1 + 7/3 ) 
Z = (9/12 - 10/12 ) ÷ ( 3/3 + 7/3 ) 
Z = (-1/12 ) ÷ (10/3 )
Z = -1/12 × 3/10
Z = -3/120
Z = -1/40