no no no

a) \(\left(\frac{3}{5}.\frac{5}{3}\right).\frac{8}{27}\)

=  \(1.\frac{8}{27}\)

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

b) \(\frac{7}{19}.\left(\frac{1}{3}.\frac{2}{3}\right)\)

= \(\frac{7}{19}.\frac{2}{9}\)

=\(\frac{14}{81}\)

Không biết có đúng không? Tick mình nha !

a)\(\frac{21}{11}x\frac{22}{17}x\frac{68}{63}\)

=\(\frac{21x22x68}{11x17x63}\)

=\(\frac{21x11x2x17x4}{11x17x21x3}\)

=\(\frac{2x4}{3}\)

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

b)\(\frac{5}{14}x\frac{7}{13}x\frac{26}{25}\)

=\(\frac{5x7x26}{14x13x25}\)

=13,25 x 2 + 13,25 x 4 + 13,25 x 8 +13,25 x6 

=13,25 x ( 2+4+8+6 ) 

= 13,25 x 20 

= 256

nhầm bằng 265 nha

\(\frac{7}{19}\)x\(\frac{1}{3}\)+\(\frac{7}{19}\)x\(\frac{2}{3}\)=\(\frac{7}{19}\)x(\(\frac{1}{3}\)+\(\frac{2}{3}\))=\(\frac{7}{19}\)x1=\(\frac{7}{19}\)

\(\frac{7}{19}\)x \(\frac{1}{3}\)x \(\frac{7}{19}\)x \(\frac{2}{3}\)

= \(\frac{7}{19}\)x (\(\frac{1}{3}\)+ \(\frac{2}{3}\))

= \(\frac{7}{19}\)x 1

= \(\frac{7}{19}\)

Chúc bạn học tốt!

em ơi cái này = 0 . Anh chắc chắn vs em 100000000000000000000000000000000000000000000000000000000000000000%

Anh lớp 7 mà

\(\frac{1}{2}:0,5-\frac{1}{4}:0,25+\frac{1}{8}:0,125-\frac{1}{10}:0,1\)

\(=\left(0,5:0,5\right)-\left(0,25:0,25\right)+\left(0,125:0,125\right)-\left(0,1:0,1\right)\)

\(=1-1+1-1\)

\(=\left(1\times2\right)-\left(1\times2\right)\)

\(=2-2\)

\(=0\)

\(13,5\div0,5+13,5\div0,125.\)

\(=13,5\times2+13,5\times8\)

\(=13,5\times\left(2+8\right)\)

\(=13,5\times10\)

\(=135\)

13,5 : 0,5  + 13,5 : 0,125  

= 13,5 : ( 0,5 + 0,125 )

= 13,5 : 0,625

= 21,6

a,

20/11*33/23*69/180

=20/180*33/11*69/23

=1/9*3*3

=1