​( 1 - x/599).(5 + 5/4 + 5/28 + ... + 5/22050)=2/3

(1- x/599).(5+5/1.4+5/4.7+...+5/147.150)=2/3

(1- x/599).(5+5-5/4+5/4-5/7+...+5/147-5/150).1/3=2/3

(1- x/599).(5+5-5/150)=2

(1- x/599).(10-5/150)=2

(1-x/599).299/30=2

1-x/599=2:299/30

1-x/599=60/299

x/599=1-60/299

x/599=239/299

x=239/299.599

x=143161/299

\(\frac{2}{3}\left(\frac{3}{5}x+\frac{1}{2}\right)=\frac{4}{5}\left(\frac{5}{6}x-\frac{4}{3}\right)+\frac{1}{2}x-\frac{4}{5}\)

\(\frac{2}{5}x+\frac{1}{3}=\frac{2}{3}x-\frac{16}{15}+\frac{1}{2}x-\frac{4}{5}\)

\(\frac{2}{5}x-\frac{2}{3}x-\frac{1}{2}x=-\frac{16}{15}-\frac{4}{5}-\frac{1}{3}\)

\(\left(\frac{2}{5}-\frac{2}{3}-\frac{1}{2}\right)x=-\frac{16}{15}-\frac{12}{15}-\frac{5}{15}\)

\(\left(\frac{12}{30}-\frac{20}{30}-\frac{15}{30}\right)x=-\frac{33}{15}\)

\(\frac{-23}{30}x=-\frac{33}{15}\)

\(x=\frac{-33}{15}:-\frac{23}{30}=\frac{-33}{15}\cdot-\frac{30}{23}=-\frac{66}{23}\)

mk k chắc nữa, tính nhẩm

Tìm x, biết:

a, \(\frac{x}{28}=\frac{-4}{7}\)

\(\Leftrightarrow x.7=\left(-4\right).28\)

\(\Leftrightarrow7x=-112\)

\(\Leftrightarrow x=-16.\)

Vậy x = - 16.

b, \(\left|x+\frac{4}{5}\right|-\frac{2}{5}=\frac{3}{5}\)

\(\Leftrightarrow\left|x+\frac{4}{5}\right|=\frac{3}{5}+\frac{2}{5}\)

\(\Leftrightarrow\left|x+\frac{4}{5}\right|=1\)

\(\Leftrightarrow\left[{}\begin{matrix}x+\frac{4}{5}=1\\x+\frac{4}{5}=-1\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=1-\frac{4}{5}\\x=-1-\frac{4}{5}\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=\frac{5}{5}-\frac{1}{5}\\x=\frac{-5}{5}-\frac{1}{5}\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=\frac{1}{5}\\x=\frac{-9}{5}\end{matrix}\right.\)

Vậy \(x=\frac{1}{5}\)hoặc \(x=\frac{-9}{5}\).

Chúc bạn hok tốt!!! lưu khánh huyền

a)\(\frac{x}{28}=\frac{-4}{7}\)

\(=>x=\frac{28.\left(-4\right)}{7}\)

\(=>x=-16\)

x=3/7 nha ban !!! K TUI NHA

X=3/7:5/7-3/11:5/11+3/13:5/13

+

1/2:5/4-1/3+1/4:5/6

=3/5-3/5+3/5 + 2/5-1/3+3/10

=3/5 +  11/10

=17/10

a)\(\left|x+\frac{1}{5}\right|-4=-2\)

\(\Rightarrow\left|x+\frac{1}{5}\right|=2\)

\(\Rightarrow x+\frac{1}{5}=2\) hoặc \(-2\)

Xét \(x+\frac{1}{5}=2\Leftrightarrow x=\frac{9}{5}\)

Xét \(x+\frac{1}{5}=-2\Leftrightarrow x=-\frac{11}{5}\)

phần a dấu + fai là dấu =

Câu b) tạm thời ko bít làm =.= 

Bài 1 : 

\(d)\) \(\frac{4^5+4^5+4^5+4^5}{3^5+3^5+3^5}.\frac{6^5+6^5+6^5+6^5+6^5+6^5}{2^5+2^5}=2x\)

\(\Leftrightarrow\)\(\frac{4^5.4}{3^5.3}.\frac{6^5.6}{2^5.2}=2x\)

\(\Leftrightarrow\)\(\frac{4^6}{3^6}.\frac{6^6}{2^6}=2x\)

\(\Leftrightarrow\)\(\frac{2^{12}}{3^6}.\frac{2^6.3^6}{2^6}=2x\)

\(\Leftrightarrow\)\(\frac{2^{12}}{3^6}.\frac{3^6}{1}=2x\)

\(\Leftrightarrow\)\(2^{12}=2x\)

\(\Leftrightarrow\)\(x=\frac{2^{12}}{2}\)

\(\Leftrightarrow\)\(x=2^{11}\)

\(\Leftrightarrow\)\(x=2048\)

Vậy \(x=2048\)

Chúc bạn học tốt ~ 

Bài 1 : 

\(a)\) Ta có : 

\(4+\frac{x}{7+y}=\frac{4}{7}\)

\(\Leftrightarrow\)\(\frac{x}{7+y}=\frac{4}{7}-4\)

\(\Leftrightarrow\)\(\frac{x}{7+y}=\frac{-24}{7}\)

\(\Leftrightarrow\)\(\frac{x}{-24}=\frac{7+y}{7}\)

Áp dụng tính chất dãy tỉ số bằng nhau ta có : 

\(\frac{x}{-24}=\frac{7+y}{7}=\frac{x+7+y}{-24+7}=\frac{22+7}{-17}=\frac{29}{-17}=\frac{-29}{17}\)

Do đó : 

\(\frac{x}{-24}=\frac{-29}{17}\)\(\Rightarrow\)\(x=\frac{-29}{17}.\left(-24\right)=\frac{696}{17}\)

\(\frac{7+y}{7}=\frac{-29}{17}\)\(\Rightarrow\)\(y=\frac{-29}{17}.7-7=\frac{-322}{17}\)

Vậy \(x=\frac{696}{17}\) và \(y=\frac{-322}{17}\)

Chúc bạn học tốt ~ 

2.

Ta có 1+2+...+n=n.(n+1):2

=>P=\(1+\frac{1}{2}.\frac{2.3}{2}+\frac{1}{3}.\frac{3.4}{2}+...+\)\(\frac{1}{16}.\frac{16.17}{2}\)=1+\(\frac{3}{2}+\frac{4}{2}+...+\frac{17}{2}\)=1+\(\frac{1}{2}.\left(3=4+..=17\right)\)

=1+\(\frac{1}{2}.153=1+\frac{153}{2}=\frac{155}{2}\)

\(\frac{1}{4}\cdot\frac{2}{6}\cdot\frac{3}{8}\cdot\frac{4}{10}\cdot....\cdot\frac{30}{62}\cdot\frac{31}{64}=2^x\)

\(\Leftrightarrow\frac{1}{2}\left(\frac{1}{2}\cdot\frac{2}{3}\cdot\frac{3}{4}\cdot.....\cdot\frac{30}{31}\cdot\frac{31}{32}\right)=2^x\)

\(\Leftrightarrow\frac{1}{32}=2^{x+1}\)

Làm nốt.

ko làm được câu này hay câu b ib với tớ nha.khẳng định tối giải.

\(a,\)\(-\frac{3}{5}\cdot x=\frac{1}{4}+0,75\)

\(-\frac{3}{5}\cdot x=\frac{1}{4}+\frac{3}{4}=\frac{4}{4}=1\)

\(x=1\div\left(-\frac{3}{5}\right)\)

\(x=-\frac{5}{3}\)

\(b,\)\(\left(\frac{1}{7}-\frac{1}{3}\right)\cdot x=\frac{28}{5}\times\left(\frac{1}{4}-\frac{1}{7}\right)\)

\(\left(\frac{3}{21}-\frac{7}{21}\right)\cdot x=\frac{28}{5}\cdot\left(\frac{7}{28}-\frac{4}{28}\right)\)

\(-\frac{4}{21}\cdot x=\frac{28}{5}\cdot\frac{3}{28}\)

\(-\frac{4}{21}\cdot x=\frac{3}{5}\)

\(x=\frac{3}{5}\div\left(-\frac{4}{21}\right)\)

\(x=-\frac{63}{20}\)

\(c,\)\(\frac{5}{7}\cdot x=\frac{9}{8}-0,125\)

\(\frac{5}{7}\cdot x=\frac{9}{8}-\frac{1}{8}\)

\(\frac{5}{7}\cdot x=1\)

\(x=1\div\frac{5}{7}\)

\(x=\frac{7}{5}\)

\(d,\)\(\left(\frac{2}{11}+\frac{1}{3}\right)\cdot x=\left(\frac{1}{7}-\frac{1}{8}\right)\cdot36\)

\(\left(\frac{6}{33}+\frac{11}{33}\right)\cdot x=\left(\frac{8}{56}-\frac{7}{56}\right)\cdot36\)

\(\frac{17}{33}\cdot x=\frac{1}{56}\cdot36\)

\(\frac{17}{33}\cdot x=\frac{9}{14}\)

\(x=\frac{9}{14}\div\frac{17}{33}\)

\(x=\frac{9}{14}\cdot\frac{33}{17}=\frac{297}{238}\)

a)\(\frac{3}{5}\times x=1\)                                        

\(x=1\div\frac{3}{5}\)

\(x=\frac{5}{3}\)

Mình chỉ làm duoc câu a thôi