Question 240561
Hello!
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If Kelly ran x number of races, we can then say Kim ran 2x-4=18.
So we now solve for x to determine how many races Kelly ran.
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{{{2x-4=18}}}
{{{2x=18+4}}}
{{{2x=22}}}
{{{x=22/2}}}
{{{x=11}}}
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Since Kelly is x, she ran 11 races.
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Let's check for Kim's number of races.
{{{2x-4=18}}}
{{{(2*11)-4=18}}}
{{{22-4=18}}}
{{{18=18}}}  ... it checks!
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Done! :)