document.write( "Question 259095: The area of my question is the evaluating of a function.
\n" ); document.write( "I am at a loss when even beginningto plug in the numbers where they need to go.\r
\n" ); document.write( "\n" ); document.write( "The problem reads: Given P(x)=4x+7, write P(-2+h)-P(-2) in simplest form.\r
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Algebra.Com's Answer #190778 by Edwin McCravy(20060)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Given P(x)=4x+7, write P(-2+h)-P(-2)\r\n" );
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document.write( "Notice that the function letter P always has a parentheses \r\n" );
document.write( "( ) right after it.  It starts off with an x in there.\r\n" );
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document.write( "Whatever is in the parentheses ( )after the function letter P is\r\n" );
document.write( "what you are supposed to substitute in place of the letter x\r\n" );
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document.write( "When you see the definition for P(x), namely this\r\n" );
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document.write( "P(x)=4x+7 \r\n" );
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document.write( "Since there are parenthese around the x after the P,\r\n" );
document.write( "to see it better, put any x's which are on the right side in \r\n" );
document.write( "parentheses too, like this:\r\n" );
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document.write( "P(x)=4(x)+7 \r\n" );
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document.write( "Now empty the x's out those parentheses like this:\r\n" );
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document.write( "P(  )=4(  )+7\r\n" );
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document.write( "That's the way you should think of a function equation. Whatever\r\n" );
document.write( "anybody puts in the parentheses on the left, that's what you must\r\n" );
document.write( "put in the parentheses on the right side.\r\n" );
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document.write( "So when you see P(-2+h)  that means to put -2+h in the parentheses\r\n" );
document.write( "on both the left and right of this\r\n" );
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document.write( "P(  )=4(  )+7\r\n" );
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document.write( "and get\r\n" );
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document.write( "P(-2+h)=4(-2+h)+7\r\n" );
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document.write( "Then you simplify the right side, (but not the left), and get\r\n" );
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document.write( "P(2+h)=-8+4h+7\r\n" );
document.write( "P(-2+h)=-1+4h\r\n" );
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document.write( "Likewise when you see P(-2)  that means to put -2 in the parentheses\r\n" );
document.write( "on both the left and right of this\r\n" );
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document.write( "P(  )=4(  )+7\r\n" );
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document.write( "and get\r\n" );
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document.write( "P(-2)=4(-2)+7\r\n" );
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document.write( "Then you simplify the right side, but not the left, and get\r\n" );
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document.write( "P(-2)=-8+7\r\n" );
document.write( "P(-2)=-1\r\n" );
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document.write( "Therefore when you see\r\n" );
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document.write( "P(-2+h)-P(-2)\r\n" );
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document.write( "since P(-2+h)=-1+4h \r\n" );
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document.write( "and\r\n" );
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document.write( "since P(-2)=-1\r\n" );
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document.write( "therefore \r\n" );
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document.write( "P(-2+h)-P(-2) \r\n" );
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document.write( "means \r\n" );
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document.write( "(-1+4h)-(-1)\r\n" );
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document.write( "then you simplify that:\r\n" );
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document.write( "P(-2+h)-P(-2) = (-1+4h)-(-1)\r\n" );
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document.write( "P(-2+h)-P(-2) = -1+4h+1\r\n" );
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document.write( "P(-2+h)-P(-2) = 4h\r\n" );
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document.write( "That's all there is to it.  It's so simple it's confusing!\r\n" );
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document.write( "Whatever is in the parentheses after the function letter,\r\n" );
document.write( "that is what you are supposed to substitute for x in the\r\n" );
document.write( "original equation for P(x).\r\n" );
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document.write( "Edwin
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