\(\frac79\times\frac{13}{17}\times\frac{17}{13}=\frac79\times\left(\frac{13}{17}\times\frac{17}{13}\right)\)

\(=\frac79\times1=\frac79\)

cảm ơn nhé

\(\frac{945x239-1}{944+945x238}\)

=\(\frac{945x\left(238+1\right)-1}{944+945x238}\)

=\(\frac{\left(945x238\right)945-1}{944+945x238}\)

=\(\frac{\left(945x238\right)+944}{944+945x238}\)=1

83,9*101

=83,9*100+83,9*1

=8390+83,9

=8473,9

Dễ mà bạn cũng ko biết sao để mình giải cho 

0,25 + 9998 +4/5+1/5+3/4

= 1/4+9998+4/5+1/5+3/4

=(1/4+3/4)+(4/5+1/5)+9998

=1+1+9998

=2+9998

=10000 

Nhớ k và ấn đúng cho mình nhé ! 

Lần sau khó mình giúp tiếp cho 

1,2 : 1,8 x 0,3=0,2

1,2 : 1,8 x 0,3 = ( 1,2 x 0,3 ) : 1,8

                     = 0,4 : 1,8

                     =  0,2

TL:

=69,78 x (75% + 1/4 + 99)

=69,78 x (3/4 + 1/4 + 99)

= 69,78 x (1 + 99)

= 69,78 x 100

= 6978

HT

6978 nha

\(\frac{1}{8}\times58,35+0,125\times41+12,5\%\times0,65\)

\(=0,125\times58,35+0,125\times41+0,125\times0,65\)

\(=0,125\times\left(58,35+41+0,65\right)\)

\(=0,125\times100\)

\(=12,5\)

\(\frac{1}{8}\)x 58,35 + 0,125 x 41 + 12,5% x 0,65

= \(\frac{1}{8}\)x 58,35 + \(\frac{1}{8}\)x 41 + \(\frac{1}{8}\)x 0,65

= \(\frac{1}{8}\)x ( 58,35 + 41 + 0,65 )

= \(\frac{1}{8}\)x 100

= 12,5

\(1\frac{1}{2}x1\frac{1}{3}:1\frac{1}{4}:1\frac{1}{5}\)

\(=\frac{3}{2}x\frac{4}{3}:\frac{5}{4}:\frac{6}{5}\)

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

\(=\frac{4x4}{2x6}=\frac{2x2x4}{2x2x3}=\frac{4}{3}\)

\(1\frac{1}{2}\times1\frac{1}{3}\div1\frac{1}{4}\div1\frac{1}{5}=\frac{3}{2}\times\frac{4}{3}\div\frac{5}{4}\div\frac{6}{5}=\frac{3}{2}\times\frac{4}{3}\times\frac{4}{5}\times\frac{5}{6}\)

                                           \(=\frac{3\times4\times4\times5}{2\times3\times5\times6}=\frac{4}{3}\)