Question

x-20%*x=7.2 đố các bạn x bằng bao nhiêu

Answer 1

x-20%*x=7.2 

=>  x .100 % - 20%.x = 7.2

=> x .(100% -20% ) = 7.2

=> x . 80% = 7.2

=> x = 7.2 : 80 % 

=> x = 9

Answer 2

\(x-20\%\times x=7,2\)

\(x-\frac{1}{5}\times x=7,2\)

\(x\times\left(1-\frac{1}{5}\right)=7,2\)

\(x\times\frac{4}{5}=7,2\)

\(x=7,2:\frac{4}{5}\)

\(x=9\)

Answer 3

x-20%*x=7.2 

=>  x .100 % - 20%.x = 7.2

=> x .(100% -20% ) = 7.2

=> x . 80% = 7.2

=> x = 7.2 : 80 % 

=> x = 9