\(\dfrac{2}{3}\)  \(\times\) \(\dfrac{1}{2}\) + \(\dfrac{3}{4}\)

= \(\dfrac{1}{3}\)    + \(\dfrac{3}{4}\)

= \(\dfrac{4}{12}\)  +  \(\dfrac{9}{12}\)

= \(\dfrac{13}{12}\)

    \(\dfrac{2}{3}\) \(\times\) \(\dfrac{1}{2}\) + \(\dfrac{3}{4}\)

=  \(\dfrac{2}{6}\) + \(\dfrac{3}{4}\)

= \(\dfrac{4}{12}\) + \(\dfrac{9}{12}\)

= \(\dfrac{13}{12}\)

/ x + 2 / > 7 

Th1 : \(x+2\ge0=>x\ge-2\)

PT trở thành :

 \(x+2>7\)

\(=>x>5\)

TH2 : \(x+2< 0=>x< -2\)

Pt trở thành :

 \(-x-2>7\)

\(=>-x=9=>x>-9\)

b) Th1 : \(x-1\ge0=>x\ge1\)

Ta có : \(x-1< 3=>x< 4\)

Th2 : \(x-1< 0=>x< 1\)

Ta có : \(-x+1< 3=>-x< 2=>x< -2\)

b: \(=\dfrac{3a-9-2a-6-6}{\left(a+3\right)\left(a-3\right)}=\dfrac{a-15}{a^2-9}\)

\(x=\dfrac{4}{27}-\dfrac{2}{3}\)

\(x=-\dfrac{14}{27}\)

\(x=\dfrac{4}{27}-\dfrac{2}{3}\)

\(x=-\dfrac{14}{27}\)

x=−1427

\(\left(\frac{13}{4}-x.\frac{8}{5}\right).3=4\)

\(\left(\frac{13}{4}-x\cdot\frac{8}{5}\right)=4:3\)

\(\frac{13}{4}-x\cdot\frac{8}{5}=\frac{4}{3}\)

\(x\cdot\frac{8}{5}=\frac{13}{4}-\frac{4}{3}\)

\(x\cdot\frac{8}{5}=\frac{23}{12}\)

\(x=\frac{23}{12}:\frac{8}{5}\)

\(x=\frac{115}{96}\)

nhanh len mik h cho

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

\(5x-3x=6\)

\(2x=6\)

\(x=3\)

5/3 x X - X =2

5/3 x X - X x1=2

(5/3-1) x X =2

2/3 x X =2

X=2:2/3

X=3

cảm ơn các bạn nhiều

-12x + 60 + 21 - 7x = 5

-19x + 81 = 5

-19x = -76

x = 4

Em chi moi hoc lop 5 thoi