Question

Tìm x

a) 3x : 2,7 = \(\dfrac{1}{3}\): \(2\dfrac{1}{4}\)

b) \(\dfrac{2x+1}{3}\)= \(\dfrac{1}{2}\)

Answer 1

a)

3x : 2,7 = \(\dfrac{1}{3}:2\dfrac{1}{4}=\dfrac{1}{3}:\dfrac{9}{4}=\dfrac{1}{3}.\dfrac{4}{9}=\dfrac{4}{27}\)

=> 3x = \(\dfrac{4}{27}\). 2,7 =\(\dfrac{1028}{270}=4\)

=> x = 4 : 3 = 1,333...

Answer 2

mình nhầm làm lại nè

a)

\(3x:2,7=\dfrac{1}{3}:2\dfrac{1}{4}=\dfrac{4}{27}\)

=> 3x : 2,7 =\(\dfrac{4}{27}.2,7=\dfrac{4}{27}.\dfrac{27}{10}=\dfrac{108}{270}\)

=> x = \(\dfrac{108}{270}:3=\dfrac{108}{810}=0,1\left(3\right)\)

Answer 3

b) \(\dfrac{2x+1}{3}=\dfrac{1}{2}\)

\(\Leftrightarrow2\left(2x+1\right)=3\)

\(\Leftrightarrow4x+2=3\)

\(\Leftrightarrow4x=3-2\)

\(\Leftrightarrow4x=1\)

\(\Leftrightarrow x=\dfrac{1}{4}\)

Vậy .......................