\(2+4+6+8+10+12+14+16+18+20+22\)
\(=\left(2+22\right)+\left(4+20\right)+\left(6+18\right)+\left(8+16\right)+\left(10+14\right)+12\)
\(=24+24+24+24+24+12\)
\(=24\times5+12\)
\(=12\times2\times5+12\)
\(=12\times\left(2\times5+1\right)\)
\(=12\times11=121\)
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tinh tong : A=2+4-6-8+10+12-14-16+18+20-22-24+.......+2004-2006-2008
2+4-6-8+10+12-14-16+18+20-22-24+......-2008
ai làm được mk tick cho
1 × 2 + 2 × 3 +3 × 4 + 4 × 5 + 5 × 6 + 6 × 7 + 7 × 8 + 8 × 9 + 9 × 10 + 10 × 11 +11 ×12 + 12 ×13 + 13×14 + 14×15 + 15×16 + 16×17 +17×18 + 18×19 + 19×20 + 20×21 + 21×22 + 22×23 + 23×24 + 24×25 + 25×26
6×7×8×9×10×11
22×20×18×16×14×12
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26+27+28+29+30=
Tính nhanh
a) 0-2+4-6+8-10+12-14+16-18+20
b) 10+11-12-13+14+15-16-17+18+19-20-21+22+23-24-25+26+27-28-29+30+31
c)99x2014-50x2014+2014
d) (81x11) :9
e)45x6+46x4
( Ai nhanh nhất , đúng nhất mình tick cho )
2+4+6+8+10+12+14+16+18+20 = ?
a) 1+3+5+7+.....+99
b)1+4+7+...28
c) 24-22+20-18+16-14+12-10+8-6
giúp mh với mh đang cần gấp huhu
B= 2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 + 18 + 20.
Tính B