Question

4/5 to 3/5 Find the percent of change. Round to the nearest tenth of a percent if necessary

Answer 1

`\cfrac{4}{5}-\cfrac{3}{5}\implies \cfrac{4-3}{5} \stackrel{ change }{\implies\cfrac{1}{5}}\quad \textit{if }(4)/(5)\textit{ is the 100\%, what's }(1)/(5)\textit{ from it in percentage?} \\\\[-0.35em] ~\dotfill`

`\begin{array}{ccll} Amount&\%\\ \cline{1-2} (4)/(5)&100\\\\ (1)/(5)&x \end{array}\implies \cfrac{~~ ( 4 )/( 5 ) ~~}{(1)/(5)}~~ = ~~\cfrac{100}{x}\implies \cfrac{4}{5}\cdot \cfrac{5}{1}=\cfrac{100}{x} \\\\\\ 4=\cfrac{100}{x}\implies 4x=100\implies x=\cfrac{100}{4}\implies x=25`