document.write( "Question 73752This question is from textbook beginning algebra
\n" ); document.write( ": the question is:
\n" ); document.write( "The given ordered pairs are solutions of the same linear equation. Find N.
\n" ); document.write( "(0,1), (4,9), (3,N)
\n" ); document.write( "The book gives the answer as 7. Fine, but how the heck did they get the answer. I can't find anything in the chapter which gives me a hint about how to solve this question. Help !! \n" ); document.write( "

Algebra.Com's Answer #52733 by Earlsdon(6294) $\"\"$ $\"About$

You can put this solution on YOUR website!
The three given points all lie on the same line, right? Why?, because, you are told, they all are solutions to the same linear equation.
\n" ); document.write( "So, we can start by finding the slope of the line, using the first two of the three points.
\n" ); document.write( " $\"m+=+%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29\"$ Substitute (0,1) and (4,9).
\n" ); document.write( " $\"m+=+%289-1%29%2F%284-0%29\"$
\n" ); document.write( " $\"m+=+8%2F4\"$
\n" ); document.write( " $\"m+=+2\"$ This is the slope of the line. The third point also lies on this line so we can use it, along with one of the other two points, in the slope formula, remembering that m = 2.
\n" ); document.write( " $\"2+=+%28N-9%29%2F%283-4%29\"$
\n" ); document.write( " $\"2+=+%28N-9%29%2F-1\"$ Multiply both sides by -1.
\n" ); document.write( " $\"-2+=+N-9\"$ Add 9 to both sides.
\n" ); document.write( " $\"7+=+N\"$ or $\"N+=+7\"$ \n" ); document.write( "

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