Đáp án A

Ta có: \(\dfrac{x}{7}-\dfrac{7}{8}=\dfrac{-25}{56}\)

\(\Leftrightarrow\dfrac{x}{7}=\dfrac{-25}{56}+\dfrac{7}{8}=\dfrac{-25+49}{56}=\dfrac{3}{7}\)

hay x=3

Vậy: x=3

\(\dfrac{x}{7}-\dfrac{7}{8}=-\dfrac{25}{56}\)

\(\Rightarrow\dfrac{x}{7}-\dfrac{49}{56}=-\dfrac{25}{56}\)

\(\Rightarrow\dfrac{x}{7}=-\dfrac{25}{56}+\dfrac{49}{56}=\dfrac{3}{7}\)

\(\Rightarrow x=3\)

\(\dfrac{x}{7}-\dfrac{7}{8}=\dfrac{-25}{56}\\ \Rightarrow\dfrac{x}{7}=\dfrac{-25}{56}+\dfrac{7}{8}\\ \Rightarrow\dfrac{x}{7}=\dfrac{24}{56}=\dfrac{3}{7}\\ \Rightarrow x=3\)

Vậy x = 3

15 nha

49 : x + 56 : x = 7

( 49 + 56 ) : x = 7

105 : x = 7

x = 105 : 7

x = 15

k mk nha

Mk cảm ơn các bạn nhiều

Thank you very much

( ^ _ ^ )

       49 : x + 56 : x = 7

<=>(49 + 56 ) : x = 7

<=>105 : x = 7

<=> x = 15.

a: x=27

a: x=27

(49+56):x=7

105:x=7

x=15

x=15 nha bạn

49:x+56:x=7

<=>(49+56):x=7

<=>105:x=7

=>x=105:7

=>x=15

\(7.(x-1).3=-56 \) 

\(3.(x-1) =-56:7\) 

\(3.(x-1)=-8\)

\(x-1=-8:3 \)

\(x-1=2,67\)

\(x=2,67+1\)

\(x=3,67\)

  số hơi lẻ

ti-ck cho mk nha

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