Question

20% . x + 2/5 . x = x - 4

Answer 1

Sửa lại -.-

20%x + 2/5x = x - 4

=> 20/100x + 2/5x - x = -4

=> 2/10x + 4/10x - 10/10x = -4

=> -4/10x = -4

=> x = -4 : -4/10

=> x = 10

Vậy x = 10

Sorry phần trên mình nhìn nhầm nha

Answer 2

\(20\%x+\frac{2}{5}x=x-4\)

\(\Rightarrow\frac{25}{100}x+\frac{2}{5}x=x-4\)

\(\Rightarrow\frac{1}{4}x+\frac{2}{5}x=x-4\)

\(\Rightarrow\frac{5}{20}x+\frac{8}{20}x=\frac{20}{20}x-4\)

\(\Rightarrow\frac{5}{20}x+\frac{8}{20}x-\frac{20}{20}x=4\)

\(\Rightarrow-\frac{7}{20}x=4\)

\(\Rightarrow x=4\div\frac{-7}{20}\)

\(\Rightarrow x=\frac{-80}{7}\)

Vậy x = \(\frac{-80}{7}\)