Question 359211
{{{abs(x)=x}}} when {{{x>=0}}}
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{{{graph(300,300,-10,10,-10,10,x)}}}
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{{{abs(x)=-x}}} when {{{x<0}}}
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{{{graph(300,300,-10,10,-10,10,-x)}}}
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Now put those two together,
{{{f(x)=abs(x)}}}
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{{{graph(300,300,-10,10,-10,10,abs(x))}}}
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The key is the argument (inside the absolute value brackets).
Make sure you understand how to find up the limits. 
So if the function is,
{{{abs(2x+4)=(2x+4)}}} when {{{2x+4>=0}}}
{{{abs(2x+4)=2x+4}}} when {{{2x>=4}}}
{{{abs(2x+4)=2x+4}}} when {{{x>=2}}}
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{{{abs(2x+4)=-(2x+4)}}} when {{{2x+4<0}}}
{{{abs(2x+4)=-2x-4}}} when {{{x<2}}}
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{{{graph(300,300,-10,10,-10,10,abs(2x-4))}}}