effectuer les calculs suivants : A= 5-5×4-9(-1) B= (3-5-8)÷(2-4) C= 15÷(-8+3)-10×(-2)

bonjour

a = 5 - 5 x 4 - 9 ( -1)
a = 5 - 20 + 9
a = - 20 + 14 = - 6

b = ( 3 - 5 -8) : ( 2 - 4)
b  = - 10 : - 2 = 5

c = 15 : ( - 5 +3) - 10 x ( - 2)
c = 15 : - 2  + 20
c = - 7.5 + 20
c = 12.5

A= 5-5×4-9(-1)
  = 5×4-9×(-1)-9+5
  = 20-(-9)-14                     
  = 20+9-14
  =29-14
  =15

B= (3-5-8)÷(2-4)
  = (-10)÷2
  = -5

C=15÷(-8+3)-10×(-2)
  =15÷(-5)-(-20)
  = -3-(-20)
  = -3+20
  = 17