1. 

= 10 000 - 29 x 11

= 10 000 - 319

= 9681

2.

= ( 3/7 + 4/7 ) + ( 4/9 + 5/9 )

= 1 + 1

= 2

A=(1+10)+(2+9)+(3+8)+...+(5+6)

A=11.5=55

B=(1+19)+(3+17)+...+(9+11)

B=20.5=100

a=(1+9) + (2+8) + (3+7) + (4+6) + 5 + 10

=10 + 10 +10 +10 +10 + 5

=55

( 7/4+5/4) x 5/3= 12/4 x 5/3 = 3 x 5/3= 5

5

5

Bạn tham khảo nhé!

a,

  97345 - 9205 x 3 + 7 x 9205

=  97345 - 9205 x (3 + 7)

=  97345 - 9205 x 10

=  97345 - 92050

= 5295

b,

4237-237x4+6x237

= 4237- 237x (4+6)

= 4237- 237x 10

= 4237- 2370

= 1867

\(\frac{3}{4}\cdot\frac{5}{7}+\frac{5}{7}\cdot\frac{1}{4}=\left(\frac{3}{4}+\frac{1}{4}\right)\cdot\frac{5}{7}=\frac{4}{4}\cdot\frac{5}{7}=1\cdot\frac{5}{7}=\frac{5}{7}\)

(lưu ý dấu . là x nhân ý)

Chúc bạn học tốt!^_^

a) 113x(54+45+1) = 113x100 = 13300.

b) 4.6x3 - 12x5 = 12x6 - 12x5 = 12x(6-5) = 12.

a/113*(54+45+1) = 113*100=13300

b/4.6*3-12*5=12*(6-5)=12

 a] 113 x {54 + 45 + 1 ]

= 113 x 100

= 11300

b]  { 24 x 3 } - { 12 x 5 }

=        72     -       60

=   12

9,6x213+213:5+213x0,1+213:10

= 9,6 x 213 + 213 x 0,2 + 213 x 0,1 + 213 x 0,1

= 213 x (9,6+0,2+0,1+0,1)

= 213 x 10= 2130

\(\left(1-\frac{1}{2}\right)\left(1-\frac{1}{3}\right)\left(1-\frac{1}{4}\right)\left(1-\frac{1}{5}\right)\left(1-\frac{1}{6}\right)\)

\(=\frac{1}{2}.\frac{2}{3}.\frac{3}{4}.\frac{4}{5}.\frac{5}{6}=\frac{1}{6}\)

\(\frac{3}{5}+\frac{6}{11}+\frac{7}{13}+\frac{2}{5}+\frac{16}{11}+\frac{19}{13}\)

\(=\left(\frac{3}{5}+\frac{2}{5}\right)+\left(\frac{6}{11}\frac{16}{11}\right)+\left(\frac{7}{13}+\frac{19}{13}\right)\)

\(=1+2+2\)

\(=5\)

a

        [3/5+2/5]+[7/13+19/13]+[6/11+16/11]=5