1933/120

mình cần giải kĩ

Sửa đề: A=5/2+5/6+...+5/2450

=5(1/2+1/6+...+1/2450)

=5(1-1/2+1/2-1/3+...+1/49-1/50)

=5*49/50<5

16:Sửa đề: \(\frac12x+\frac16\left(x-2\right)=\frac34-2x\)

=>\(\frac12x+\frac16x-\frac26=\frac34-2x\)

=>\(\frac46x-\frac13=\frac34-2x\)

=>\(\frac23x+2x=\frac34+\frac13\)

=>\(\frac83x=\frac{9}{12}+\frac{4}{12}=\frac{13}{12}\)

=>\(x=\frac{13}{12}:\frac83=\frac{13}{12}\times\frac38=\frac{13}{4\times8}=\frac{13}{32}\)

19: \(\frac{5}{12}x+3=\frac13-\frac{7}{12}x\)

=>\(\frac{5}{12}x+\frac{7}{12}x=\frac13-3\)

=>\(\frac{12}{12}x=\frac13-\frac93=-\frac83\)

=>\(x=-\frac83\)

20: \(\frac12x+\frac52=\frac72x-\frac34\)

=>\(\frac12x-\frac72x=-\frac34-\frac52\)

=>\(-3x=-\frac34-\frac{10}{4}=-\frac{13}{4}\)

=>\(3x=\frac{13}{4}\)

=>\(x=\frac{13}{4}:3=\frac{13}{12}\)

A

a

\(\frac{20}{16}+\frac{3}{15}+\frac{2}{12}+\frac{3}{4}+\frac{4}{5}+\frac{5}{6}\)

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

\(=\left(\frac{5}{4}+\frac{3}{4}\right)+\left(\frac{1}{5}+\frac{4}{5}\right)+\left(\frac{1}{6}+\frac{5}{6}\right)\)

\(=2+1+1\)

\(=4\)

=4 nhé

lồn chó sủa

Gyug : Hãm loz bn êy

2/3 + 7/1 = 2/3 + 7 = 2/3 + 21/3 = 23/3

25/48 + 11/24 = 25/48 + 22/48 = 47/48

5/7 + 3/8 = 40/56 + 21/56 = 61/56

15/24 + 12/6 = 5/8 + 2 = 5/8 + 16/8 = 21/8

5/6 + 4/3 = 5/6 + 8/6 = 13/6

3/8 + 7/12 = 9/24 + 14/24 = 23/24

= 23/3

= 47/48

=61/56

=21/8

=13/6

= 23/24

M = \(\frac32\) - \(\frac56\) + \(\frac{7}{12}\) - \(\frac{9}{20}\) + \(\frac{11}{30}\) - \(\frac{13}{42}\) + \(\frac{15}{56}\) - \(\frac{17}{72}\)

M = \(\frac{3}{1.2}\) - \(\frac{5}{2.3}\) + \(\frac{7}{3.4}\) - \(\frac{9}{4.5}\) + \(\frac{11}{5.6}\) - \(\frac{13}{6.7}\) + \(\frac{15}{7.8}\) - \(\frac{17}{8.9}\)

M = \(\frac11+\frac12\) - \(\frac12-\frac13\) +....+\(\frac17+\frac18\) - \(\frac18\) - \(\frac19\)

M = \(\frac11\) - \(\frac19\)

M = \(\frac89\)