aidez moi svp pour demain

bonsoir

a = 21 + 9  = 30

b = 12 x 20

c  =  19 x 10

d = 81 x 20

Bonsoir

a)3×7+3×3

=3(7+3)

=3×10

=30

b)12×17+12×3

=12(17+3)

=12×20

=240

c)15×19-5×19

=19(15-5)

=19×10

=190

d)23×81-3×81

=81(23-3)

=81×20

=1620

Et voilà! ;)