a) = \(\left(\dfrac{2}{7}+\dfrac{4}{7}+\dfrac{1}{7}\right):\dfrac{27}{31}\)

= \(\dfrac{7}{7}\) x \(\dfrac{31}{27}\)

= 1 x \(\dfrac{31}{27}\) = \(\dfrac{31}{27}\)

b) = \(\left(\dfrac{23}{45}:\dfrac{23}{45}\right)\)x \(\dfrac{17}{51}\)

= 1 x \(\dfrac{17}{51}\)= \(\dfrac{17}{51}\)

A = \(\dfrac{36\times950+18\times726\times2+3\times324\times12}{1+3+5+7+...+27+29+31-152}\)

A = \(\dfrac{36\times950+36\times726+36\times324}{1+3+5+7+...+27+29+31-152}\)

MS = 1 + 3 + 5 +...+ 27 + 29 + 31 - 152

Xét dãy số: 1; 3; 5;...;27; 29; 31 là dãy số cách đều với khoảng cách là:  

                    3 - 1 = 2

Số số hạng của dãy số là: 

                 (31 - 1): 2 + 1 = 16

MS = (31 + 1) x 16 : 2 - 152 = 104

A = \(\dfrac{36\times\left(950+726+324\right)}{104}\)

A = \(\dfrac{36\times2000}{104}\)

A = \(\dfrac{9000}{13}\)

ratg gsvs bsnb bzn zh svhs smsm sns c xbx ja js s nx xhxxb same gj hbgg  jcu buyxcvyt u

53644

như thế ai lm nổi

trốc tru vừa thôi

\(\frac{27}{8}-\frac{7}{3}+\frac{4}{3}-2\)

=\(\frac{27}{8}-\left(\frac{7}{3}-\frac{4}{4}\right)-2\)

=\(\frac{27}{8}-1-2\)

=\(\frac{27}{8}-\frac{8}{8}-\frac{16}{8}\)

=\(\frac{3}{8}\)

sai hết

12,46-4,9-5,1

=12,46-(4,9+5,1)

=12,46-10

=2,46

a)12,46-4,9-5,1

=12,46-(4,9+5,1)

=12,46-10

=2,46

27/8 - 7/3 + 4/3 - 2

= 27/8 -  (7/3 - 4/3) - 2

= 27/8 - 1 - 2

=27/8 - 3

= 3/8 

= 27/8-(7/3-4/3)-1

=27/8-1-1

=27/8-2

=11/8

- Ủng hộ -

~minhanh~

=3/8 nha ban 

25 x 5 x 4 x 27 x 2 = 27000

25 . 5 . 4 . 27 . 2

= ( 25 . 4 ) . ( 5 . 2 ) . 27

=    100  .  10 .   27

=       1000    .    27

=          27 000

Ta có: 25.5.4.27.2 = (25.4).(5.2).27
                                 = 100.10.27 = 27000

Lời giải:
$=27\times 2+12,44\times 4+17,56\times 4+23\times 2$

$=2\times (27+23)+4\times (12,44+17,56)$

$=2\times 50+4\times 30$

$=100+120=220$

    27 * 4 + 27 * 6

= 27 * ( 4 + 6 )

= 27 * 10

= 270

    73 * 2 + 73 * 8

= 73 * ( 2 + 8 )

= 73 * 10

= 730

27*4+27*6=27*(4+6)=27*10=270

73*2+73*8=73*(2+8)=73*10=730

27 x 4 + 27 x 6

= 27 x ( 4 + 6 )

= 27 x 10

= 270

73 x 2 + 73 x 8

= 73 x ( 2 + 8 )

= 73 x 10

= 730