1.

\(\left(572\cdot7+266\right)\cdot\left(366\cdot9-168\cdot18\right)\cdot\left(346\cdot6-348\right)\)

\(=\left(286\cdot7\cdot2+133\cdot2\right)\cdot\left(366\cdot9-168\cdot2\cdot9\right)\cdot\left(173\cdot6\cdot2-174\cdot2\right)\)

\(=\left(2002\cdot2+133\cdot2\right)\cdot\left(366\cdot9-336\cdot9\right)\cdot\left(1038\cdot2-174\cdot2\right)\)

\(=\left[2\cdot\left(2002+133\right)\right]\cdot\left[9\cdot\left(366-336\right)\right]\cdot\left[2\cdot\left(1038-174\right)\right]\)

\(=2\cdot2135\cdot9\cdot30\cdot2\cdot864\)

\(=4270\cdot9\cdot30\cdot2\cdot864\)

\(=\left(4270\cdot30\right)\cdot9\cdot2\cdot864\)

\(=\left(427\cdot10\right)\cdot\left(3\cdot10\right)\cdot9\cdot2\cdot864\)

\(=\left(427\cdot3\right)\cdot\left(10\cdot10\right)\cdot9\cdot2\cdot864\)

\(=1281\cdot100\cdot9\cdot2\cdot864\)

\(=\left(1281\cdot100\right)\cdot\left(9\cdot2\cdot864\right)\)

\(=\left(1281\cdot100\right)\cdot15552\)

\(=\left(1281\cdot15552\right)\cdot100\)

\(=19922112\cdot100\)

\(=1992211200\)

2.

\(\left(1+3+5+7+...+97+9\right)\cdot\left(45\cdot3-15\cdot2-45\right)\)

\(=\left(1+3+5+7+...+97+9\right)\cdot\left(15\cdot3\cdot3-15\cdot2-15\cdot3\right)\)

\(=\left(1+3+5+7+...+97+9\right)\cdot\left[15\cdot\left(3\cdot3\right)-15\cdot2-15\cdot3\right]\)

\(=\left(1+3+5+7+...+97+9\right)\cdot\left(15\cdot9-15\cdot2-15\cdot3\right)\)

\(=\left(1+3+5+7+...+97+9\right)\cdot\left[15\cdot\left(9-2-3\right)\right]\)

\(=\left(1+3+5+7+...+97+9\right)\cdot15\cdot4\)

\(=\left[\left(1+3+5+7+...+97\right)+9\right]\cdot\left(15\cdot4\right)\)

Trong \(\left(1+3+5+7+...+97\right)\) có số số hạng là:

        \(\left(97-1\right)\div2+1=49\) ( số hạng )

\(\Rightarrow\left[\left(1+3+5+7+...+97\right)+9\right]\cdot\left(15\cdot4\right)\)

\(=\left[\left(97+1\right)\cdot49\div2\right]\cdot\left(15\cdot4\right)\)

\(=2401\cdot60\)

\(=\left(2401\cdot6\right)\cdot10\)

\(=14406\cdot10\)

\(=144060\)

3.

\(\left(180\div15-132\div11\right)\cdot\left(57869-297\div11\cdot108\right)\)

\(=\left(12-12\right)\cdot\left(57869-297\div11\cdot108\right)\)

\(=0\cdot\left(57869-297\div11\cdot108\right)\)

\(=0\)

Sửa lại bài 2; dòng 11 ( từ đề bài bài 2 ):

\(=\left\{\left[\left(97+1\right)\cdot49\div2\right]+9\right\}\cdot\left(15\cdot4\right)\)

\(=\left(2401+9\right)\cdot\left(15\cdot4\right)\)
\(=2410\cdot\left(15\cdot4\right)\)

\(=2410\cdot60\)

\(=\left(241\cdot10\right)\cdot\left(6\cdot10\right)\)

\(=\left(241\cdot6\right)\cdot\left(10\cdot10\right)\)

\(=1446\cdot10\)

\(=14460\)

793476480

2.9241805e+26

xàm??

.-. ?

spam à

14dm5cm=14,5dm;3dm7cm=3,7dm

chu vi hình chữ nhật đó là:

(14,5+3,7)x2=36,4(dm)

ĐS:36,4dm

14 dm 5 cm = 14,5 dm 

3 dm 7 cm = 3,7 dm 

Chiều rộng HCN là :

14,5 - 3,7 = 10,8 ( dm )

chu vi HCN là :

( 14,5 + 10,8 ) x 2 = 50,6 ( dm )

ĐS:..

8 + 1 = 9     7 + 2 = 9     6 + 3 = 9     5 + 4 = 9

1 + 8 = 9     2 + 7 = 9     3 + 6 = 9     4 + 5= 9

9 - 8 = 1     9 - 7 = 2     9 - 6 = 3     9 - 5 = 4

9 - 1 = 8     9 - 2 = 7     9 - 3 = 6     9 - 4 = 5

Lời giải chi tiết:

2=1+1          6=2+4          8=5+3          10=8+2

3=1+2          6=3+3          8=4+4          10=7+3

4=3+1          7=6+1          9=8+1          10=6+4

4=2+2          7=5+2          9=7=2          10=5+5

5=4+1          7=4+3         9=6+3           10=10+0

5=3+2          8=7+1         9=5=4           10=0+10

6=5+1          8=6=2         10=9+1         1=0+1

\(\dfrac{8}{9}:\dfrac{3}{7}=\dfrac{56}{27}\\ \dfrac{8}{9}+\dfrac{2}{5}=\dfrac{58}{45}\\ \dfrac{7}{8}-\dfrac{1}{3}=\dfrac{13}{24}\\ \dfrac{3}{10}\times\dfrac{1}{6}=\dfrac{1}{20}\\ 1\dfrac{2}{7}+6\dfrac{5}{6}=\dfrac{9}{7}+\dfrac{41}{6}=\dfrac{341}{42}\\ 5\dfrac{3}{4}-\dfrac{1}{5}=\dfrac{23}{4}-\dfrac{1}{5}=\dfrac{111}{20}\\ 6\dfrac{2}{9}:4\dfrac{7}{10}=\dfrac{56}{9}:\dfrac{47}{10}=\dfrac{560}{423}\\ \dfrac{5}{3}+\dfrac{3}{2}-\dfrac{7}{6}=2\)

sao có bn làm đươc công tác viên vậy

2 = 1 + 1     6 = 2 + 4     8 = 5 + 3     10 = 8 + 2

3 = 1 + 2     6 = 3 + 3     8 = 4 + 4     10 = 7 + 3

4 = 3 + 1     7 = 1 + 6     9 = 8 + 1     10 = 6 + 4

4 = 2 + 2     7 = 5 + 2     9 = 6+ 3     10 = 5 + 5

5 = 4 + 1     7 = 4 + 3     9 = 7 + 2     10 = 10 + 0

5 = 3 + 2     8 = 7 + 1     9 = 5 + 4     10 = 0 + 10

6 = 5 + 1     8 = 6 + 2     10 = 9 + 1     1 = 1 + 0

Tiếng  việt  khó .