Cách 1:

     \(\dfrac{3}{7}\) x \(\dfrac{16}{33}\) + \(\dfrac{16}{33}\) x \(\dfrac{4}{7}\)

=    \(\dfrac{48}{231}\) + \(\dfrac{64}{231}\)

= \(\dfrac{112}{231}\)

= \(\dfrac{16}{33}\)

cách 2:  \(\dfrac{3}{7}\) x \(\dfrac{16}{33}\) + \(\dfrac{16}{33}\) x \(\dfrac{4}{7}\)

       = \(\dfrac{16}{33}\) x ( \(\dfrac{3}{7}\) + \(\dfrac{4}{7}\))

      = \(\dfrac{16}{33}\) x \(\dfrac{7}{7}\)

     = \(\dfrac{16}{33}\)

9,3×6,7+3,3

\(\frac{3}{7}x\frac{16}{33}+\frac{16}{33}x\frac{4}{7}\)

\(C1:=\frac{16}{77}+\frac{64}{231}=\frac{16}{33}\)

\(C2:=\frac{16}{33}\left(\frac{3}{7}+\frac{4}{7}\right)=\frac{16}{33}.1=\frac{16}{33}\)

học tốt ~~~

C1:3/7×16/33+16/33×4/7

=48/231+64/231

=112/231

C2:3/7×16/33+16/33×4/7

=16/33×(3/7+4/7)

=16/33×7/7

=113/231

C1 : \(\frac{3}{7}\times\frac{16}{33}+\frac{16}{33}\times\frac{4}{7}\)

\(=\frac{16}{77}+\frac{64}{231}\)

\(=\frac{16}{33}\)

C2 : \(\frac{3}{7}\times\frac{16}{33}+\frac{16}{33}\times\frac{4}{7}\)

\(=\frac{16}{33}\times\left(\frac{3}{7}+\frac{4}{7}\right)\)

\(=\frac{16}{33}\times1\)

\(=\frac{16}{33}\)

a. ….= 61 692 : 4 = 15 423

….= 33 164 : 4 + 28 528 : 4

….= 8291 + 7132 = 15 423

b. ….= 387 079 : 7 = 55 297

….= 403 494 : 7 – 16 414 : 7

….= 57 642 - 2345 = 55 297

mình cần gấp lắm giúp mình nha mấy bạn

đéo biết!!! Nhưng đừng có chửa tui ngu nha!! Tại tui lười ấy!!

Hướng dẫn giải:

a) 93 + 39 + 7 = (93 + 7) + 39 = 100 + 39 = 139.

89 + 85 + 11 = (89 + 11) + 85 = 100 + 85 = 185

184 + 66 + 16 = (184 + 16) + 66 = 200 + 66 = 266

b) 23 + 52 + 47 + 98 = (23 + 47) + (52 + 98) = 70 + 150 = 220

16 + 490 + 84 + 10 = (16 + 84) + (490 + 10) = 100 + 500 = 600 

b . 3/7 . 16/33 + 16/33 . 4/7

=   16/33 . ( 3/7 + 4/7 ) 

=    16/33 . 7/7

=     16/33 . 1

=   16/33 

c2    3/7 . 16/33 + 16/33 . 4/7

=      16/77 + 64/231

=     48/231 + 64/231 

=              112/231

=      16/33 

chúc em học giỏi !!! 

a . 5/24 . 5/12 . 24

= ( 5/24 . 24 ) .5/12

=    5 . 5/12

= 25/12 

C2 :           5/24 . 5/12 . 24 

=      5/24 . ( 5/12 . 24 ) 

=      5/24 . 10 

=    50/24

= 25/12 

Câu 5:

a: \(31\cdot\left(-18\right)+31\cdot\left(-81\right)-31\)

\(=31\left(-18-81-1\right)\)

\(=31\cdot\left(-100\right)=-3100\)

b: \(\left(-12\right)\cdot47+\left(-12\right)\cdot52+\left(-12\right)\)

\(=\left(-12\right)\left(47+52+1\right)\)

\(=-12\cdot100=-1200\)

c: \(13\cdot\left(23+22\right)-3\cdot\left(17+28\right)\)

\(=13\cdot45-3\cdot45\)

\(=45\cdot10=450\)

d: \(-48+48\left(-78\right)+48\left(-21\right)\)

\(=48\left(-1-78-21\right)\)

\(=48\left(-100\right)=-4800\)

Câu 4:

a: \(\left(-6-2\right)\left(-6+2\right)=\left(-8\right)\cdot\left(-4\right)=32\)

b: \(\dfrac{\left(7\cdot3-3\right)}{-6}=\dfrac{21-3}{-6}=\dfrac{18}{-6}=-3\)

c: \(\left(-5+9\right)\cdot\left(-4\right)=4\cdot\left(-4\right)=-16\)

d: \(\dfrac{72}{-6\cdot2+4}=\dfrac{72}{-12+4}=\dfrac{72}{-8}=-9\)