document.write( "Question 1097061: 2/3y + 1/4x = 2
\n" ); document.write( "8y + 3x = a
\n" ); document.write( "in this system of equations a is a constant.If the system has infinite solutions, what is the value of a?
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Algebra.Com's Answer #711459 by josh_jordan(263)\"\" \"About 
You can put this solution on YOUR website!
In order for a system to have infinitely many solutions, you must have a situation where, when you add the two equations in the system together, your result is 0 = 0. (zero on the left side of the equation and zero on the right) \r
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\n" ); document.write( "\n" ); document.write( "To find the value of a so that the system has infinite solutions, let's start by getting rid of the fractions from equation 1 in our system. To do this, we can multiply the entire equation by 12, which is the least common denominator. This gives us\r
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\n" ); document.write( "\n" ); document.write( "8y + 3x = 24\r
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\n" ); document.write( "\n" ); document.write( "Notice how the left side of equation 1 now matches the left side of equation 2?\r
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\n" ); document.write( "\n" ); document.write( "8y + 3x = 24
\n" ); document.write( "8y + 3x = a\r
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\n" ); document.write( "\n" ); document.write( "This tells us that in order for both equations to match, \"a\" MUST be 24. So, if a is 24, let's try to solve our system. What will happen?\r
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\n" ); document.write( "\n" ); document.write( "First, we can multiply equation 1 by -1, giving us\r
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\n" ); document.write( "\n" ); document.write( "-8y - 3x = -24
\n" ); document.write( "8y + 3x = 24\r
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\n" ); document.write( "\n" ); document.write( "Adding equation 1 and 2 together, we get:\r
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\n" ); document.write( "\n" ); document.write( "0 = 0\r
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\n" ); document.write( "\n" ); document.write( "Since 0 = 0, this system of linear equations has infinitely many solutions when a = 24.\r
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\n" ); document.write( "\n" ); document.write( "Answer: a = 24
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