document.write( "Question 1011330: In a multiple choice test there are 20 questions. A correct answer to a question earns 2 marks, and an incorrect answer results in a deduction of one mark. Sarah acheived a mark of 19. How many questions did she get right? \n" ); document.write( "

Algebra.Com's Answer #626942 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+x+\"$ = number of questions she got right
\n" ); document.write( " $\"+20+-+x+\"$ = number she got incorrect
\n" ); document.write( "---------------------------------
\n" ); document.write( " $\"+2x+-+1%2A%28+20+-+x+%29+=+19+\"$
\n" ); document.write( " $\"+2x+-+20+%2B+x+=+19+\"$
\n" ); document.write( " $\"+3x+=+39+\"$
\n" ); document.write( " $\"+x+=+13+\"$
\n" ); document.write( "She got 13 questions right
\n" ); document.write( "------------------------
\n" ); document.write( "check:
\n" ); document.write( " $\"+2x+-+1%2A%28+20+-+x+%29+=+19+\"$
\n" ); document.write( " $\"+2%2A13+-+1%2A%28+20+-+13+%29+=+19+\"$
\n" ); document.write( " $\"+26+-+20+%2B+13+=+19+\"$
\n" ); document.write( " $\"+39+-+20+=+19+\"$
\n" ); document.write( " $\"+19+=+19+\"$
\n" ); document.write( "OK \n" ); document.write( "

\n" );