Question

three times a number decreased by 20 is equal to the excess of said number over 4 finds the number

Answer 1

${\text{Let the required number be }}x. \hfill \\ \Rightarrow 3x - 20 = x + 4 \hfill \\ {\text{Adding 20 both sides, we get}} \hfill \\ \Rightarrow 3x - 20 + 20 = x + 4 + 20 \hfill \\ \Rightarrow 3x = x + 24 \hfill \\ {\text{Subtracting }}x{\text{ from both sides, we get}} \hfill \\ \Rightarrow 3x - x = x + 24 - x \hfill \\ \Rightarrow 3x - x = x - x + 24 \hfill \\ \Rightarrow 2x = 24 \hfill \\ {\text{Dividing both sides by 2, we get}} \hfill \\ \frac{{2x}}{2} = \frac{{24}}{2} \hfill \\</p><p>\Rightarrow x = 12,{\text{required number}}{\text{.}} \hfill$