Question

3×1+3×3+3×5+3×7+3×9+.....+3×21myry

Answer 1

3(1+3+5+7+9+…+21)=
3(1+2•1+1+2•2+1+2•3+1+2•4+1+…+2•10+1) =
3[1+2(1+2+3+4+…+10)]=
3[1+2(10•11):2]=
3(1+110)=
3•111=333
Sper că te-an ajutat!Spor La scris! ;-)

Answer 2

3 x (1+3+5+7+9+…+21)=
3 x (1+2x0+1+2x1+1+2x2+1+2x3+1+2x4+1+…+2x10+1) =
3 x [1+2 x (1+2+3+4+…+10)]=
3 x [1+2 x (10x11):2]=
3 x (1+110)=
3 x 111=333