document.write( "Question 398712: Hello,
\n" ); document.write( "I have linear equation problem that I am stuck on. I have tried the problem myself but I'm having trouble with it. Here is the problem I'm working on:\r
\n" ); document.write( "\n" ); document.write( "Determine the necessary conditions on a, b and c for the following systems to have:
\n" ); document.write( "a unique solution; an in finite number of solutions; or be inconsistent.\r
\n" ); document.write( "\n" ); document.write( "x1 + ax2 = 5
\n" ); document.write( "3x1 + 6x2 = b\r
\n" ); document.write( "\n" ); document.write( "Here is the work I've done so far, and this is all in matrices so imagine the boxes around the numbers:
\n" ); document.write( "1 a |5
\n" ); document.write( "3 6 |b\r
\n" ); document.write( "\n" ); document.write( "multiplying row 2 by 1/3
\n" ); document.write( "1 a | 5
\n" ); document.write( "1 2 | b/3\r
\n" ); document.write( "\n" ); document.write( "subtracting row 1 from row 2
\n" ); document.write( "1 a |5
\n" ); document.write( "0 2-a |b/3 - 5\r
\n" ); document.write( "\n" ); document.write( "I'm not sure if what I've done is correct, but this is where I'm stuck because I do not know how to set up the three conditions?
\n" ); document.write( "Thank you for any help
\n" ); document.write( "Yury
\n" ); document.write( "

Algebra.Com's Answer #282433 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
Determine the necessary conditions on a, b and c for the following systems to have:
\n" ); document.write( "a unique solution; an in finite number of solutions; or be inconsistent.
\n" ); document.write( "x1 + ax2 = 5
\n" ); document.write( "3x1 + 6x2 = b
\n" ); document.write( "---
\n" ); document.write( "Put in slope-intercept form:
\n" ); document.write( "x1 = -ax2 + 5
\n" ); document.write( "slope = -a
\n" ); document.write( "int = 5
\n" ); document.write( "---------
\n" ); document.write( "x1 = -2x2 - (b/3)
\n" ); document.write( "slope = -2
\n" ); document.write( "int = (-b/3)
\n" ); document.write( "============================
\n" ); document.write( "Unique solution when slopes are not equal:
\n" ); document.write( "-a is not equal to -2
\n" ); document.write( "a is not equal to 2
\n" ); document.write( "--------------------
\n" ); document.write( "Inconsistent when slopes are equal.
\n" ); document.write( "-a = -2
\n" ); document.write( "a = 2
\n" ); document.write( "---------------
\n" ); document.write( "Infinite # of solutions when slopes and int are equal.
\n" ); document.write( "a=2
\n" ); document.write( "and (-b/3) = 5
\n" ); document.write( "b = -15
\n" ); document.write( "===================
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
\n" ); document.write( "
\n" );