Question 997308
{{{x}}}= the original number
When it is decreased by {{{"30%"}}}, what is left is
{{{"100%"-"30%"="70%"=70/100=0.7}}} of {{{x}}} .
That is {{{0.7x}}} .
When {{{0.7x}}} is doubled, the result is
{{{2*(0.7x)}}} , and that equals {{{91}}} .
The equation that state that is
{{{2*(0.7x)=91}}} .
Solving:
{{{2*(0.7x)=91}}} can be simplified to {{{1.4x=91}}} , because
{{{2*(0.7x)=91}}}<-->{{{(2*0.7)x=91}}}<-->{{{1.4x=91}}} .
then,
{{{1.4x=91}}}-->{{{x=91/1.4}}}-->{{{x=65}}}