Question 1107798
What six steps?


x, how many gallons of 80% antifreez

PRESENT:  80 gallons of 20% antifreeze

WANT:   70% antifreeze



{{{(20*80+80*x)/(80+x)=70}}}, Basic Equation


-

{{{20*80+80x=70*(80+x)}}}
{{{2*80+8x=7(80+x)}}}
{{{2*80+8x=7*80+7x}}}
{{{x=5*80}}}
{{{highlight(x=400)}}}
Four Hundred Gallons of 80% material be added.


CHECK?

{{{(20*80+80*400)/480}}}

{{{(2*80+8*400)/48}}}

{{{70}}}

{{{okay}}}