Question

Tìm số nguyên xx thỏa mãn:

-3x + 30/21 = 6/7

Answer 1

nhanh giúp mình với 

Answer 2

\(\Rightarrow-3x=\dfrac{6}{7}-\dfrac{30}{21}\\ \Rightarrow-3x=\dfrac{18}{21}-\dfrac{30}{21}\\\Rightarrow-3x=\dfrac{-12}{21}\\ \Rightarrow x=\dfrac{-12}{21}:3\\ \Rightarrow x=\dfrac{-12}{63}=\dfrac{-4}{21} \)

Answer 3

-3x+\(\dfrac{30}{21}=\dfrac{6}{7}\)

=>-3x=\(\dfrac{6}{7}-\dfrac{30}{21}\)

=>-3x=\(\dfrac{18-30}{21}\)

=>-3x=\(\dfrac{-12}{21}\)

=>x=\(\dfrac{-12}{21}.\dfrac{1}{3}\)

=>x=\(\dfrac{-12}{63}=\dfrac{-4}{21}\)

Vậy ......