document.write( "Question 24428: this is my question: Determine whether the system has one solution,no solution, or many solutions: y=2/3x
\n" ); document.write( " 2x-y=-4\r
\n" ); document.write( "\n" ); document.write( "could somebody please explain how to get the answer? Thank you.
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Algebra.Com's Answer #13010 by Earlsdon(6294)\"\" \"About 
You can put this solution on YOUR website!
The first equation is ambiguous!
\n" ); document.write( "Is it \"y+=+%282%2F3%29x\" or \"y+=+2%2F3x\"???
\n" ); document.write( "Let's assume that it is the first case.\r
\n" ); document.write( "\n" ); document.write( "You can solve questions like this by graphing or algebraically.
\n" ); document.write( "Let's look at the graphic solution:
\n" ); document.write( "\"graph%28300%2C200%2C-5%2C5%2C-5%2C5%2C%282%2F3%29x%2C2x%2B4%29\"
\n" ); document.write( "The red line is \"y+=+%282%2F3%29x\"
\n" ); document.write( "The green line is \"y+=+2x%2B4\" This is the 2nd equation written in terms of y.\r
\n" ); document.write( "\n" ); document.write( "Now solve algebraically by substitution:
\n" ); document.write( "1) \"y+=+%282%2F3%29x\" Substitute this equation for y in the second equation.
\n" ); document.write( "2) \"2x-y+=+-4\"\r
\n" ); document.write( "\n" ); document.write( "2) \"2x-%282%2F3%29x+=+-4\" Simplify and solve for x.
\n" ); document.write( "\"%284%2F3%29x+=+-4\" Multiply both sides by the multiplicative inverse of 4/3 (that's 3/4)
\n" ); document.write( "\"x+=+-3\" Now substitute this value of x into either one of the two original equations and solve for y. Take the first equation, \"y+=+%282%2F3%29x\"
\n" ); document.write( "\"y+=+%282%2F3%29%28-3%29\"
\n" ); document.write( "\"y+=+-2\"\r
\n" ); document.write( "\n" ); document.write( "There is only one solution, it is: (-3, -2) Compare this with the intersection point of the two lines on the graph.\r
\n" ); document.write( "\n" ); document.write( "Now assume that the first equation is: \"y+=+2%2F3x\" and let's look at the graph:
\n" ); document.write( "\"graph%28300%2C200%2C-5%2C5%2C-5%2C5%2C2%2F%283x%29%2C2x%2B4%29\"
\n" ); document.write( "As you can see, there would be two solutions (points of intersection) in this case.
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