Calculeaza după model.

a) 6x(3+7)=6x3+6x7=18+42=60
8x(5+4)=8x5+8x4=40+32=72
7x(6+3)=7x6+7x3=42+21=63
b) (9+4)x2=2x9+2x4=18+8=26
(6+5)x5=5x6+5x5=30+25=55
(4+6)x6=6x4+6x6=23+36=59