Question 460033


The function{{{ f(x) = 180x/100-x}}} 

{{{f(x)}}}, in millions of dollars, to remove{{{ x}}}% of a river's pollutants 

the government commits ${{{60}}} ...->...{{{f(x)=60}}}

{{{ 60= 180x/100-x}}} ....both sides multiply by {{{100}}}

{{{ 60*100= 180*100x/100-100x}}} 

{{{ 6000= 180x-100x}}} .......solve for {{{x}}}


{{{ 6000= 80x}}}

{{{ 600cross(0)= 8cross(0)x}}}

{{{ 600= 8x}}}

{{{ 600/8= x}}}

{{{ 75= x}}}

so, {{{75}}} % of the pollutants can be removed