document.write( "Question 655221: How do I determine f(-20) from a graph? \n" ); document.write( "
Algebra.Com's Answer #408978 by MathLover1(20855)\"\" \"About 
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\n" ); document.write( "\"+f%28-20%29\" tells you that \"x=-20\"\r
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\n" ); document.write( "\n" ); document.write( "construct a vertical line at \"x=-20\" and see where it meets the graph
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