a) \(-5x+\frac{1}{2}=\frac{2}{3}\\ -5x=\frac{2}{3}-\frac{1}{2}\\ -5x=\frac{1}{6}\\ x=\frac{1}{6}:\left(-5\right)\\ x=\frac{-1}{30}\)Vậy \(x=\frac{-1}{30}\)

b) \(\frac{1}{-5}-\frac{2}{3}+1\frac{1}{2}x=\frac{1}{2}\\ \frac{-13}{15}+\frac{3}{2}x=\frac{1}{2}\\ \frac{3}{2}x=\frac{1}{2}-\frac{-13}{15}\\ \frac{3}{2}x=\frac{41}{30}\\ x=\frac{41}{30}:\frac{3}{2}\\ x=\frac{41}{45}\)Vậy \(x=\frac{41}{45}\)

c) \(2\left(\frac{1}{4}-3x\right)=\frac{1}{5}-4x\\ \frac{1}{2}-6x=\frac{1}{5}-4x\\ \frac{1}{2}-\frac{1}{5}=6x-4x\\ \frac{3}{10}=2x\\ x=\frac{3}{10}:2\\ x=\frac{3}{20}\)Vậy \(x=\frac{3}{20}\)

d) \(\frac{-5}{2}-3\left(\frac{1}{3}-x\right)=\frac{1}{4}-7x\\ \frac{-5}{2}-1+3x=\frac{1}{4}-7x\\ \frac{-7}{2}+3x=\frac{1}{4}-7x\\ 7x+3x=\frac{1}{4}+\frac{7}{2}\\ 10x=\frac{15}{4}\\ x=\frac{15}{4}:10\\ x=\frac{3}{8}\)Vậy \(x=\frac{3}{8}\)

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

⇔\(\frac{-5x.6}{6}+\frac{3}{6}=\frac{4}{6}\)

➞\(30x+3=4\)

⇔\(30x=1\)

⇔\(x=\frac{1}{30}\)

\(\frac{2}{7}+\frac{7}{12}=\frac{24}{84}+\frac{49}{84}=\frac{73}{84}\)

\(\frac{25}{48}+\frac{22}{48}=\frac{47}{48}\)

\(\frac{5}{7}+\frac{3}{8}=\frac{40}{56}+\frac{21}{56}=\frac{61}{56}\)

\(\frac{15}{24}+\frac{15}{16}=15.\left(\frac{1}{24}+\frac{1}{16}\right)=\frac{25}{16}\)

\(\frac{5}{6}+\frac{3}{4}=\frac{20+18}{24}=\frac{19}{12}\)

\(\frac{9}{24}+\frac{14}{24}=\frac{23}{24}\)

học tót tích mình hem

2/7 + 7/12 = 73/84.

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

5/7 + 3/8 = 61/56.

15/24 + 15/16 = 25/16.

5/6 + 3/4 = 19/12.

3/8 + 7/12 = 23/24.

hok tốt!

\(\frac{2}{7}+\frac{7}{12}=\frac{24}{84}+\frac{49}{84}=\frac{73}{84}\)

\(\frac{25}{48}+\frac{11}{24}=\frac{25}{48}+\frac{22}{48}=\frac{47}{48}\)

\(\frac{5}{7}+\frac{3}{8}=\frac{40}{56}+\frac{21}{56}=\frac{61}{56}\)

\(\frac{5}{6}+\frac{3}{4}=\frac{20}{24}+\frac{18}{24}=\frac{38}{24}=\frac{19}{12}\)

\(\frac{3}{8}+\frac{7}{12}=\frac{36}{96}+\frac{56}{96}=\frac{92}{96}=\frac{23}{24}\)

Học tốt

2) \(\left(x-5\right)\left(x^2+1\right)=0\)

\(\Rightarrow x-5=0\) vì \(x^2+1>0\)

\(\Rightarrow x=5\)

cAU 1 TƯƠNG TỰ NHÉ 

Tương tự sao được

a/ \(30.\left\{x+2+6\left(x-5\right)\right\}-24x=102\)

\(\Leftrightarrow30.\left\{x+2+6x-30\right\}-24x=102\)

\(\Leftrightarrow30.\left\{7x-28\right\}-24x=102\)

\(\Leftrightarrow210x-340-24x=102\)

\(\Leftrightarrow186x-340=102\)

\(\Leftrightarrow186x=442\)

\(\Leftrightarrow x=\frac{442}{186}\)

c/ \(\left(x+1\right)+\left(x+2\right)+....+\left(x+99\right)=0\)

\(\Leftrightarrow\left(x+x+...+x\right)+\left(1+2+......+99\right)=0\)

\(\Leftrightarrow99x+49500=0\)

\(\Leftrightarrow x=-50\)

thì mình bảo câu 1 làm tươgn tự nhé, còn câu 3 ko làm tương tự đc, hiểu ko bạn  Thanh Hằng Nguyễn

dễ mak

Bài 1 :

1) a² - 4 + y ( a - 2 )

= ( a + 2 ) ( a - 2 ) + y ( a - 2 )

= ( a - 2 ) ( a + 2 + y )

2) ( x - 2 )² - 9y²

= ( x - 2 - 3y ) ( x - 2 + 3y )

Bài 2 :

1) 3 ( x + 4 ) - 2x = 5

=> 3x + 12 - 2x = 5

=> x + 12 = 5

=> x = 5 - 12 = - 7

Vậy x = - 7

2) x ( x - 2 ) - x² - 6 = 0

=> x² - 2x - x² - 6 = 0

=> - 2x - 6 = 0

=> 2x = - 6

=> x = \(-\frac{6}{2}=3\)

Vậy x = 3

3 ) x² - 3x = 0

=> x ( x - 3 ) = 0

=> \(\orbr{\begin{cases}x=0\\x-3=0\end{cases}}\)

=> \(\orbr{\begin{cases}x=0\\x=3\end{cases}}\)

Vậy \(x\in\left\{0;3\right\}\)

4) 5 - 3 ( x - 6 ) = 4

=> 5 - 3x + 18 = 4

=> 3x = 5 + 18 - 4

=> 3x = 19

=> x = \(\frac{19}{3}\)

Vậy \(x=\frac{19}{3}\)

Thanks nhìu nha😍😍😍😍

Ta có

\(\frac{1}{2}=\frac{1\times3\times5}{2\times3\times5}=\frac{15}{30}\)

\(\frac{1}{3}=\frac{1\times2\times5}{3\times2\times5}=\frac{10}{30}\)

\(\frac{2}{5}=\frac{2\times2\times3}{5\times2\times3}=\frac{12}{30}\)

Hok tốt !!!!!!!!!!!!!!!!!!!

a, 48

b, 21

Còn bài tính n bạn xem lại đề kết quả của tổng bằng mấy, ko có tổng ko làm đc bạn à

Bài này ko có kết quả à

(x+1)+(x+2)+(x+3).........(x+1000)

=x+1+x+2+...+x+1000

=1000x+(1+2+3+...+1000)

=1000x+(1000-1+1).(1000+1):2=500500+1000x

\(\left(x+1\right)+\left(x+2\right)+\left(x+3\right)+...+\left(x+1000\right)\)

\(=\left(x+x+x+...+x\right)+\left(1+2+3...+1000\right)\)

= \(1000x+500500\)