Question 394432
let number be {{{x}}}

Five times a number is {{{5x}}}

subtracted from {{{40}}}is


 {{{40 - 5x}}} which is  same as three times the number {{{3x}}}


so, you have:


 {{{40 - 5x = 3x}}}


{{{40 - 5x + 5x = 3x + 5x}}}


{{{40  = 8x }}}


{{{40/8  = x }}}


{{{5  = x }}}