2 câu trả lời
Đáp án:
1+3+5+7+9+11+13+15+17+19
= (19+1) + (17+3) + (15+5) + (13+7) + (11+9)
= 20 + 20 + 20 + 20 + 20
= 100
1+3+5+7+9+11+13+15+17+19
= (19+1)+(3+17)+(5+15)+(7+13)+(9+11)
= 20 + 20 + 20 + 20 + 20
= 5 x 20
= 100
Đáp án:
1+3+5+7+9+11+13+15+17+19
= (19+1) + (17+3) + (15+5) + (13+7) + (11+9)
= 20 + 20 + 20 + 20 + 20
= 100
1+3+5+7+9+11+13+15+17+19
= (19+1)+(3+17)+(5+15)+(7+13)+(9+11)
= 20 + 20 + 20 + 20 + 20
= 5 x 20
= 100