Question

a) \(\dfrac{2}{7}-\dfrac{8}{9}.x=\dfrac{2}{3}\)

b) \(\dfrac{2}{5}-\dfrac{2}{5}x=\dfrac{2}{5}\)

c) \(\dfrac{2}{9}-\dfrac{7}{8}x=\dfrac{1}{3}\)

Answer 1

a) \(\dfrac{8}{9}x=\dfrac{2}{7}-\dfrac{2}{3}=-\dfrac{8}{21}\)

\(x=-\dfrac{8}{21}:\dfrac{8}{9}=-\dfrac{3}{7}\)

 

b) \(\dfrac{2}{5}x=\dfrac{2}{5}-\dfrac{2}{5}=0\)

\(x=0:\dfrac{2}{5}=0\)

c)\(\dfrac{7}{8}x=\dfrac{2}{9}-\dfrac{1}{3}=-\dfrac{1}{9}\)

\(x=-\dfrac{1}{9}:\dfrac{7}{8}=-\dfrac{8}{63}\)

Answer 2

a) 2/7 - 8/9 . x = 2/3

⇒ 8/9 . x = 2/7 - 2/3 

⇒ 8/9 .x = -8/21

⇒ x = -8/21 : 8/9

⇒ x = -3/7.

Vậy...

 

Answer 3

b) 2/5 - 2/5x = 2/5

⇒ 2/5x = 0

⇒ x = 0.

Vậy...

Answer 4

c) 2/9 - 7/8x = 1/3

⇒ 7/8x = 2/9 - 1/3 

⇒ 7/8x = -1/9

⇒ x = -1/9 : 7/8

⇔ x = -8/63.

Vậy...