5.63+4.63+3.63+2.63+63

=63(4.63+3.63+2.63+63+1)

=63(252+189+126+64)

=63.631=39753

nha

5.63+4.63+3.63+2.63+63

=63(5+4+3+2+1)

=63.15

=945

học tốt nha bn

nhớ k nha

ta có 2.S=4/2.6+4/6.10+...+4/96.100

suy ra 2S1/2-1/6+1/6-1/10+...+1/96-1/100

suy ra 2S=1/2-1/100

suy ra 2S=49/100

suy ra S=49/200

vậy S= 49/200

bài này mình làm đúng như cô giáo mình giảng .mình ko làm tắt nên các bạn cứ yên tâm

cảm ơn

ta có 2.S=4/2.6+4/6.10+...+4/96.100

suy ra 2S1/2-1/6+1/6-1/10+...+1/96-1/100

suy ra 2S=1/2-1/100

suy ra 2S=49/100

suy ra S=49/200

vậy S= 49/200

3 : 6,25 = 0,48

483 : 35 = 13,8

98,156 : 4,63 =21,2

0.48

13.8

21.2

\(S=\frac{8.2+2.14+2.90+2.6+2.12}{2.3.4+2.8+2.79+2.11}\)

     \(=\frac{2\left(8+14+90+6+12\right)}{2\left(3.4+8+79+11\right)}\)

     \(=\frac{130}{110}\)

     \(=\frac{13}{11}\)

\(S=\frac{2\cdot\left(8+14+90+6+12\right)}{2.\left(3.4+8+79+11\right)}=\frac{2.130}{2.110}=\frac{130}{110}=\frac{13}{11}\)

Nếu đúng cho L ike nhé !

\(S=\frac{2\left(8+14+90+6+12\right)}{2\cdot\left(3.4+8+79+11\right)}=\frac{130}{110}=\frac{13}{11}\)

(1,4 + 2,6) x 2 = 4 x 2 = 8

70 : (4,6 + 3,4 - 1) = 70 : 7 = 10

\(\left(1,4+2,6\right)\times2\)

\(=4\times2=8\)

\(70\div\left(4,6+3,4-1\right)\)

\(=70\div7=10\)

(1,4 + 2,6) x 2 = 4 x 2 = 8

70 : ( 4,6 + 3,4 - 1) = 70 : 7 = 10

Đặt A = 1/2.6 + 1/6.10 + 1/10.14 + ..... + 1/102.106

=> 4A = 4/2.6 + 4/6.10 + 4/10.14 + ..... + 4/102.106

=> 4A = 1/2 - 1/6 + 1/6 - 1/10 + 1/10 - 1/14 + ... + 1/102 - 1/106

=> 4A = 1/2 - 1/106

=> 4A = 26/53

=> A = 13/106

~Study well~

#QASJ

\(\frac{1}{2.6}+\frac{1}{6.10}+...+\frac{1}{102.106}\)

\(=\frac{1}{4}.\left(\frac{4}{2.6}+\frac{4}{6.10}+...+\frac{4}{102.106}\right)\)

\(=\frac{1}{4}.\left(\frac{1}{2}-\frac{1}{6}+\frac{1}{6}-\frac{1}{10}+...+\frac{1}{102}-\frac{1}{106}\right)\)

\(=\frac{1}{4}.\left(\frac{1}{2}-\frac{1}{106}\right)\)

\(=\frac{1}{4}.\frac{26}{53}\)

\(=\frac{13}{106}\)

Đặt \(B=\frac{1}{2.6}+\frac{1}{6.10}+\frac{1}{10.14}+...+\frac{1}{102.106}\)

\(\Leftrightarrow4B=\frac{4}{2.6}+\frac{4}{6.10}+\frac{4}{10.14}+...+\frac{4}{102.106}\)

\(\Leftrightarrow4B=\frac{1}{2}-\frac{1}{6}+\frac{1}{6}-\frac{1}{10}+\frac{1}{10}-\frac{1}{14}+...+\frac{1}{102}-\frac{1}{106}\)

\(\Leftrightarrow4B=\frac{1}{2}-\frac{1}{106}=\frac{26}{53}\)

\(\Leftrightarrow B=\frac{26}{53}:4=\frac{13}{106}\)

Vậy ...................

~ Hok tốt ~