TÍNH THEO CẶP ĐI

 2 SỐ NÀO + LẠI =  SỐ TRÒN THÌ LÀ 1 CẶP

Quá dễ: = (12,78 + 87,22) + (435,81 + 64,19) + (11+89) = 100 + 500 + 100 = 700             

12,78 + 435,81 + 89 + 64,19 + 11 + 87,22 = 700

Chúc bạn học tốt!

89 x 11 + 11 x 11

= 11 x ( 89 + 11 )

= 11 x 100 = 1100

89 x 11 + 11 x 11

= 11 x (89 + 11)

= 11 x 100

= 1100

89 x 11 + 11x 11

=11 x ( 89 + 11)

= 11 x 100

= 1 100

11 x 10 + 89 x 5 + 89 x 3 + 89 x 2

= 110 + 89 x ( 5 + 3 + 2)

= 110 + 89 x 10

= 110 + 890

= 1000

\(1000\)

a ) 11 x 10 + 89 x 5 + 89 x 3 + 89 x 2

= 11 x 10 + 89 x ( 5 + 3 + 2 )

= 11 x 10 + 89 x 10

= ( 11 + 89 ) x 10

=  100 x 10

= 1000

`a)79+65 = 79 + (21+44)=(79+21)+44=100+44=144`

`b) 996 + 45 = 996+(41+4)=(996+4)+41=1000+41=1041`

`c) 37 + 198 = (35+2)+198=35+(2+198)=35+200 = 235`

`c) 3492 + 319 = 3492+(311+8)=(3492+8)+311=3500+311=3811`

a) 79+65=(79+21)+44=100+44=144

b) 996+45=(996+4)+41=1000+41=1041

dễ nhưng ko tính

\(=\frac{111}{11}\)

111/11

tick chao minh nha

là 111/11

tik nha bạnNguyễn thị Hằng  yêu quý!

\(49(82+18)+100+50(89+11)\)

\(=49\cdot100+100+50\cdot100\)

\(=100\left(49+50+1\right)\)

\(=100\cdot100=10000\)

49 . (82 + 18) + 100 + 50 . (89 + 11)

= 49 . 100 + 100 + 50 . 100

= 100.(49 + 1 + 50)

= 100 . 100

= 10000

Tớ sửa chút, phải bằng 10

  1/2 + 5/6 + 11/12 + ... + 89/90 + 109/110 + 10/11

= (1 - 1/2) + (1 - 1/6) + (1 - 1/12) + ... + (1 - 1/90) + (1 - 1/110) + 10/11

= (1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1) - (1/1*2 + 1/2*3 + 1/3*4 + ... + 1/10*11) + 10/11

= 9 - (1 - 1/11) + 10/11

= 9 - 10/11 + 10/11 = 9

T=1/2+5/6+11/12+...+89/90+109/110+10/11

T= (1 -1/2) + ( 1 - 1/6) + (1-1/12) + (1-1/20)+(1-1/30)+... + (1 - 1/90) + (1- 1/110) + 10/11

T= 1x10 –(1/2+1/6+1/12+1/20+……..+1/90+1/110)+10/11

T=10 – (1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+……+1/9-1/10+1/10-1/11)+ 10/11

T= 10 – (1-1/11)+10/11 = 10-10/11+10/11

T=10