\(\dfrac{15}{8}\)

x : 5/9 = 3/72

      x : 5/9 = 1/24

      x = 1/24 x 5/9

      x = 5 / 216

\(x:\dfrac{5}{9}=\dfrac{3}{72}\)

\(x=\dfrac{3}{72}\cdot\dfrac{5}{9}\)

\(x=\dfrac{5}{216}\)

a)-12(x-5)+7(3-x)=5

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

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

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

-19x=-76

x=-76/-19

x=4. Vậy x=4

ặc, bạn ghi ít ít thôi, ghi thế này nhiều quá

72-3|x+1|=9

<=>3|x+1|=63

<=>|x+1|=21

Xét TH1: x+1>0

 <=>x+1=21

<=>x=20

Xét TH2: x+1<0

<=>x+1=-21

<=>x=-22

Vậy x=20 hoặc x=-22

sorry em ko biết

a) \(\frac{5}{12}=\frac{x}{72}\Rightarrow x=\frac{5.72}{12}=30\)

b)\(\frac{x+3}{15}=\frac{1}{3}\)

\(\Rightarrow x+3=\frac{15.1}{3}=5\)

\(\Rightarrow x=5-3=2\)

c)\(\frac{-2}{9}=\frac{x}{72}\Rightarrow x=\frac{-2.72}{9}=-16\)

a) 5/12=30/72

b) 2+3/15=1/3

c) -2/9=-16/72

Chắc chắn đúng nha các bạn !

Ủng hộ mình nha các bạn !

\(\frac{x}{1,5}=\frac{4}{3}\Rightarrow x=\frac{4.1,5}{3}=2\)

\(\frac{2}{9}=\frac{x}{-72}\Rightarrow x=\frac{2.\left(-72\right)}{9}=-16\)

\(x:-\frac{3}{8}=\frac{1}{3}\)

\(x=\frac{1}{3}.\left(-\frac{3}{8}\right)\)

\(x=-\frac{1}{8}\)

tick cho mk nha:

a) \(\frac{x}{1,5}=\frac{4}{3}\)   \(\Rightarrow x=1,5\times4\div3\)  =2 .

b)  \(\frac{2}{9}=\frac{x}{-72}\)   \(\Rightarrow x=-72\times2\div9\)  = \(-16\)

c) \(x\div\frac{-3}{8}=\frac{1}{3}\)  \(\Rightarrow x=\frac{1}{3}\times\frac{-3}{8}\)   \(x=\frac{-1}{8}\)

chúc bn hc tốt nha!

1)15x-9x+2x=(15-9+2)x=8x=72

x=72:8=9

2)3^x+2+3^x=3^x.3²+3^x=3^x.9+3^x.1=3^x.(9+1)=3^x.10=10

3^x=10:10=1

3^x=1=3⁰

=>x=0

ko hiểu thì ? đừng k sai nha!

1)15x-9x+2x=72

x(15-9)+2x=72

x6+2x=72

x(6+2)=72

x8=72

x=72:8

x=9

Vay x=9

\(a.15x-9x+2x=72\)

\(\Rightarrow x\left(15-9+2\right)=72\)

\(\Rightarrow x.8=72\)

\(\Rightarrow x=72:8\)

\(\Rightarrow x=9\)

\(b.3^{x+2}+3^x=10\)

\(\Rightarrow3^x.3^2+3^x=10\)

\(\Rightarrow3^x\left(3^2+1\right)=10\)

\(\Rightarrow3^x.10=10\)

\(\Rightarrow3^x=1\)

\(\Rightarrow x=0\)