Răspuns :
1. ac+bc
a=9-b c=5
(9-b)× 5+ ( b ×5)=
9×5-b×5 +b×5=
45-5b+ 5b=45
ac+bc=45
2. a-b=4; c=10
ac-bc=?
a=4+b
(4+b)×10-(10b)=40+10b-10b=40
ac-bc=40
a=9-b c=5
(9-b)× 5+ ( b ×5)=
9×5-b×5 +b×5=
45-5b+ 5b=45
ac+bc=45
2. a-b=4; c=10
ac-bc=?
a=4+b
(4+b)×10-(10b)=40+10b-10b=40
ac-bc=40