Răspuns :
ex6 a) 8×(40+45)= 8×85= 680.
8×40+8×45=320+360= 680.
b) 9×(120-15)= 9×105= 945.
9×120-9×15=1080-135= 945.
ex7 ;rezolvarea 20-12=8, 8+4=12.
8×40+8×45=320+360= 680.
b) 9×(120-15)= 9×105= 945.
9×120-9×15=1080-135= 945.
ex7 ;rezolvarea 20-12=8, 8+4=12.