document.write( "Question 206266: An old grading system describes grades from 0 to 10. New grading guidelines require that grades be entered from 50 to 100. Which expression can be used to convert an old grade, g, to the new grade?\r
\n" ); document.write( "\n" ); document.write( "A) 5g
\n" ); document.write( "B) g+50
\n" ); document.write( "C) g+90
\n" ); document.write( "D) 10g-50
\n" ); document.write( "E) 5g+50
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Algebra.Com's Answer #155833 by Edwin McCravy(20059)\"\" \"About 
You can put this solution on YOUR website!
An old grading system describes grades from 0 to 10. New grading guidelines require that grades be entered from 50 to 100. Which expression can be used to convert an old grade, g, to the new grade?\r
\n" ); document.write( "\n" ); document.write( "A) 5g
\n" ); document.write( "B) g+50
\n" ); document.write( "C) g+90
\n" ); document.write( "D) 10g-50
\n" ); document.write( "E) 5g+50
\n" ); document.write( "
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document.write( "Such an expression would have to convert g=0 to 50, and g=10 to 100.\r\n" );
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document.write( "Let's try each of those answers and see which, if any, of them\r\n" );
document.write( "do that.\r\n" );
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document.write( "Let's try:\r\n" );
document.write( "

\n" ); document.write( "A) 5g
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\r\n" );
document.write( "Let's see if 5g converts g=0 to 50:\r\n" );
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document.write( "Substituting 0 in 5g gives 5(0) or 0.  No that doesn't convert\r\n" );
document.write( "g=0 to 50. It converts it back to 0.  So there is no use trying \r\n" );
document.write( "to see if it converts g=10 to 100.  (It doesn't, btw)\r\n" );
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document.write( "So we have ruled out choice A)\r\n" );
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document.write( "Let's try out\r\n" );
document.write( "

\n" ); document.write( "B) g+50
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\r\n" );
document.write( "Let's see if g+50 converts g=0 to 50:\r\n" );
document.write( "\r\n" );
document.write( "Substituting 0 in g+50 gives 0+0 or 50.  YES, that does convert\r\n" );
document.write( "g=0 to 50. However it also must convert g=10 to 100.\r\n" );
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document.write( "Let's see if g+50 converts g=10 to 100: \r\n" );
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document.write( "Substituting 10 in g+50 gives 10+50 or 60.  NO, that does convert\r\n" );
document.write( "g=10 to 100. It converts it to 60. \r\n" );
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document.write( "So we have ruled out choice A)\r\n" );
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document.write( "Let's try out:\r\n" );
document.write( "

\n" ); document.write( "C) g+90
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\r\n" );
document.write( "\r\n" );
document.write( "Let's see if g+90 converts g=0 to 50:\r\n" );
document.write( "\r\n" );
document.write( "Substituting 0 in g+90 gives 0+90 or 90.  No that doesn't convert\r\n" );
document.write( "g=0 to 50. It converts it to 90.  So there is no use trying \r\n" );
document.write( "to see if it converts g=10 to 100.  (It DOES, btw! but it doesn't\r\n" );
document.write( "convert 0 to 50)\r\n" );
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document.write( "So we have ruled out choice C)\r\n" );
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document.write( "Let's try out:\r\n" );
document.write( "

\n" ); document.write( "D) 10g-50
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\r\n" );
document.write( "Let's see if 10g-50 converts g=0 to 50:\r\n" );
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document.write( "Substituting 0 in 10g-50 gives 10(0)-50 or -50.  No that doesn't convert\r\n" );
document.write( "g=0 to 50. It converts it to -50.  So there is no use trying \r\n" );
document.write( "to see if it converts g=10 to 100.  (It DOES, btw! but it doesn't\r\n" );
document.write( "convert 0 to 50)\r\n" );
document.write( "\r\n" );
document.write( "So we have ruled out choice D)\r\n" );
document.write( "\r\n" );
document.write( "Let's try out:\r\n" );
document.write( "

\n" ); document.write( "E) 5g+50
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\r\n" );
document.write( "Let's see if 5g+50 converts g=0 to 50:\r\n" );
document.write( "\r\n" );
document.write( "Substituting 0 in 5g+50 gives 5(0)+50 or 50.  YES that does convert\r\n" );
document.write( "g=0 to 50.  However it also must convert g=10 to 100.\r\n" );
document.write( "\r\n" );
document.write( "Let's see if 5g+50 converts g=10 to 100: \r\n" );
document.write( "\r\n" );
document.write( "Substituting 10 in 5g+50 gives 5(10)+50 or 100. YES, that does convert\r\n" );
document.write( "g=10 to 100. \r\n" );
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document.write( "So the correct choice is E)\r\n" );
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document.write( "Edwin
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