1+2+3+4+5+6+7+8+9= 45
2+2+2+2+2+2+2+2+2+2= 20
10+20+30+49+50+60+70+80+90= 459
1+2+3+4+5+6+7+8+9=45
2+2+2+2+2+2+2+2+2+2=20
10+20+30+40+50+60+70+80+90=450
Học tốt tích rồi mình kết bạn cho
1+2+3+4+5+6+7+8+9=45
2+2+2+2+2+2+2+2+2+2=20
10+20+30+49+50+60+70+80+90=450
1+2+3+4+5+6+7+8+9=45
2+2+2+2+2+2+2+2+2+2=20
10+20+30+40+50+60+70+80+90=450
1+2+3+4+5+6+7+8+9=45
2+2+2+2+2+2+2+2+2+2=20
10+20+30+49+50+60+70+80+90=450
1+2+3+4+5+6+7+8+9=45
2+2+2+2+2+2+2+2+2+2=20
10+20+30+40+50+60+70+80+90=450
1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 = ( 1 + 9 ) + ( 2 + 8 ) + ( 3 + 7 ) + ( 4 + 6 ) + 5
= 10 + 10 + 10 + 10 + 5 = 55
2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2
= 2 x 10 = 20
10 + 20 + 30 + 40 + 50 + 60 + 70 + 80 + 90 = ( 10 + 90 ) + ( 20 + 80 ) + ( 30 + 70 ) + ( 40 + 60 ) + 50
= 100 + 100 + 100 + 100 + 50 =450
1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 = 45
2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 = 20
10 + 20 + 30 + 40 + 50 + 60 + 70 + 80 + 90 = 450
1+2+3+4+5+6+7+8+9=45
2+2+2+2+2+2+2+2+2+2 = 20
10+20+30+40+50+60+70+80+90 = 450
1+2+3+4+5+6+7+8+9=45
2+2+2+2+2+2+2+2+2+2=20
10+20+30+49+50+60+70+80+90=459
tk mk nha mn