\(\frac{4}{15}:y=\left(\frac{4}{5}+\frac{1}{2}\right)\times\frac{4}{13}\)

\(\frac{4}{15}:y=\frac{13}{10}\times\frac{4}{13}\)

\(\frac{4}{15}:y=\frac{2}{5}\)

\(y=\frac{4}{15}:\frac{2}{5}\)

\(y=\frac{2}{3}\)

\(\frac{4}{15}:y=\left(\frac{8}{10}+\frac{5}{10}\right)X\frac{4}{13}\)

\(\frac{4}{15}:y=\frac{13}{10}X\frac{4}{13}\)

\(\frac{4}{15}:y=\frac{2}{5}\)

\(y=\frac{4}{15}:\frac{2}{5}\)

\(y=\frac{4}{15}X\frac{5}{2}\)

\(y=\frac{2}{3}\)

HOK TỐT

Bài 1:

a) \(=\dfrac{8}{15}\left(\dfrac{7}{13}+\dfrac{6}{13}\right)=\dfrac{8}{15}.1=\dfrac{8}{15}\)

b) \(=\dfrac{3.3-7-2.4}{12}=-\dfrac{6}{12}=-\dfrac{1}{2}\)

Bài 2:

 \(\dfrac{x}{2,7}=-\dfrac{2}{3,6}\Rightarrow x=\dfrac{\left(-2\right).2,7}{3,6}\Rightarrow x=-\dfrac{3}{2}\)

Bài 3:

\(\dfrac{x}{2}=\dfrac{y}{5}=\dfrac{x+y}{2+5}=-\dfrac{21}{7}=-3\)

\(\Rightarrow\left\{{}\begin{matrix}x=\left(-3\right).2=-6\\y=\left(-3\right).5=-10\end{matrix}\right.\)

giúp mik dzới

1.

7/15:(1/2-9/10xX)-1/6=13/6

=>7/15:(1/2-9/10xX)=13/6+1/6

=>7/16:(1/2-9/10xX)=7/3

=>1/2-9/10xX=7/16:7/3

=>1/2-9/10xX=3/16

=>9/10xX=1/2-3/16

=>9/10xX=5/16

=>X=5/16:9/10

=>X=25/72

a) Ta có |x-5|=13

suy ra x-5=13 hoặc x-5=-13

suy ra x=18 hoặc x=-13

b) |x-3|<4

suy ra x-3<4 hoặc 3-x<4

suy ra x<7 hoặc x >-1

c) d) e) f) y) tương tự nha bạn!

2: Tọa độ giao điểm là:

\(\left\{{}\begin{matrix}2x-1=x+1\\y=x+1\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=2\\y=3\end{matrix}\right.\)