\(=\dfrac{2x-x-5+x-5}{\left(x+5\right)\left(x-5\right)}=\dfrac{2}{x+5}\)

Sai

\(\left(2x-1\right):\dfrac{10}{7}=\dfrac{28}{15}:\dfrac{4}{3}\)

\(\Rightarrow\left(2x-1\right).\dfrac{7}{10}=\dfrac{28}{15}.\dfrac{3}{4}\)

\(\Rightarrow\left(2x-1\right).\dfrac{7}{10}=\dfrac{7}{5}\)

\(\Rightarrow2x-1=\dfrac{7}{5}:\dfrac{7}{10}\)

\(\Rightarrow2x-1=\dfrac{7}{5}.\dfrac{10}{7}\)

\(\Rightarrow2x-1=2\)

\(\Rightarrow2x=3\)

\(\Rightarrow x=\dfrac{3}{2}\)

Cảm ơn bạn

(-6x + 1)(x + 5) + 6x²

= -6x(x + 5) + 1(x + 5) + 6x²

= -6x² - 30x + x + 5 + 6x²

= (-6x² + 6x²) + (-30x + x) + 5

= -29x + 5

\(\left(-6x+1\right)\left(x+5\right)+6x^2\)

\(=-6x.\left(x+5\right)+1\left(x+5\right)+6x^2\) ( nhân đa thức với đa thức)

\(=-6x^2-30+x+5+6x^2\)

\(=-29x+5\)

x=-18

x =18

9/15 và 5/15 nhé

\(\dfrac{9}{15}=\dfrac{9}{15}\\ \dfrac{1}{3}=\dfrac{1\times5}{3\times5}=\dfrac{5}{15}\)

\(\Leftrightarrow x^3-3x^2+3x-1-2x+3x^2-2+6x=-3\)

\(\Leftrightarrow x^3+7x-5=0\)

\(x+-\dfrac{1}{9}=-\dfrac{1}{6}\)

\(\Rightarrow x-\dfrac{1}{9}=-\dfrac{1}{6}\)

\(\Rightarrow x=-\dfrac{1}{6}+\dfrac{1}{9}\)

\(\Rightarrow x=-\dfrac{1}{18}\)

_______________

\(5x-3x-\dfrac{5}{6}=\dfrac{2}{3}\)

\(\Rightarrow2x-\dfrac{5}{6}=\dfrac{2}{3}\)

\(\Rightarrow2x=\dfrac{2}{3}+\dfrac{5}{6}\)

\(\Rightarrow2x=\dfrac{3}{2}\)

\(\Rightarrow x=\dfrac{3}{2}:2\)

\(\Rightarrow x=\dfrac{3}{4}\)

đúng k bn

x+1/6=x+8/3

\(\Leftrightarrow\)x-x=8/3-1/6

\(\Leftrightarrow\)0x=15/6 (vô nghiệm)

\(x+\dfrac{1}{6}=x+\dfrac{8}{3}\)

\(x-x=\dfrac{8}{3}-\dfrac{1}{6}=\dfrac{15}{6}\)(vô nghiệm)

a) \(\dfrac{-5}{9}-\dfrac{4}{15}+\dfrac{2}{9}-\dfrac{11}{15}\)

\(=\left(\dfrac{-5}{9}+\dfrac{2}{9}\right)-\left(\dfrac{4}{15}+\dfrac{11}{15}\right)\)

\(=\dfrac{-3}{9}-\dfrac{15}{15}\)

\(=-\dfrac{1}{3}-1\)

\(=-\dfrac{4}{3}\)

b) \(\dfrac{-8}{13}-\dfrac{7}{16}+\dfrac{21}{13}-\dfrac{1}{6}\)

\(=\left(\dfrac{-8}{13}+\dfrac{21}{13}\right)-\dfrac{7}{16}-\dfrac{1}{6}\)

\(=\dfrac{13}{13}-\dfrac{29}{48}\)

\(=1-\dfrac{29}{48}\)

\(=\dfrac{19}{48}\)

c) \(\dfrac{-15}{25}-\dfrac{14}{21}+\dfrac{8}{5}-\dfrac{5}{3}\)

\(=\dfrac{-3}{5}-\dfrac{2}{3}+\dfrac{8}{5}-\dfrac{5}{3}\)

\(=\left(\dfrac{-3}{5}+\dfrac{8}{5}\right)-\left(\dfrac{2}{3}+\dfrac{5}{3}\right)\)

\(=\dfrac{5}{5}-\dfrac{7}{3}\)

\(=1-\dfrac{7}{3}\)

\(=-\dfrac{4}{3}\)

a: =-5/9+2/9-11/15-4/15

=-3/9-1

=-12/9=-4/3

b: =-8/13+21/13-7/16-1/6

=1-1/6-7/16

=5/6-7/16

=19/48

c: =-15/25+8/5-2/3-5/3

=-7/3+1

=-4/3

=>36/18>x>8/15

=>2>x>8/15

mà x nguyên

nên x=1