Calculer a la main A= 78-8X7+3 B=19+9-7+2 C=57+3X(47-8) merci bcp

à la main donc sans calculatrice

a  = 78 - 56 + 3
a = 81 - 56 = 25

b = 31 - 7

c = 57 + 3 * 39
c = 57 + 117 = 174

A = 78 - (8 x 7) + 3
A = 78 - 56 + 3
A = 78 - 53
A = 25


B = 19 + 9 - 7 + 2
B = 30 - 7
B = 23


C = 57+ 3(47 - 8)
C = 57+ 141 - 24
C = 198 - 24
C = 174