Question

Rezolvați Ecuatiile: 2/5x=3/10+1/2 ; 0,3x-1=0,2 ; 2x:4/5=10/3 ; 3/4:x=3/8 ; -5/14:x+1,25=0

Answer 1

$\it1)\ \dfrac{2}{5}x=\dfrac{3}{10}+\dfrac{1}{2} \Big{|}_{\cdot{10}}\Rightarrow4x=3+5\Rightarrow 4x=8\Rightarrow x=2\\\\\\2)\ 0,3x-1=0,2\Big{|}_{\cdot10} \Rightarrow 3x-10=2 \Rightarrow 3x=2+10 \Rightarrow3x=12 \Rightarrow x=4\\\\\\3)\ 2x:\dfrac{4}{5}=\dfrac{10}{3} \Rightarrow 2x\cdot\dfrac{5}{4}=\dfrac{10}{3} \Rightarrow x\cdot\dfrac{5}{2}=\dfrac{10}{3} \Rightarrow x=\dfrac{10}{3}\cdot\dfrac{2}{5} \Rightarrow x=\dfrac{4}{3}$

$\it 4)\ \dfrac{3}{4}:x=\dfrac{3}{8} \Rightarrow \dfrac{3}{4}=\dfrac{3}{8} \cdot x \Rightarrow x=\dfrac{3}{4}\cdot\dfrac{8}{3} \Rightarrow x=2$

Answer 2

2x/5=3/10+1/2 (factor comun 10)

4x=3+5

4x=8

x=2

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0,3x-1=0,2

0,3x=1,2

x=4

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2x*5/4=10/3

5x/2=10/3

15x=20

x=4/3

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3/4: x=3/8

x=8:4=2

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-5/14:x + 1,25=0

-0,35/x= -1,25

x=3,57