document.write( "Question 504909: Write a system of two linear equations that has .
\n" ); document.write( "a) only one solution ,(5,1).
\n" ); document.write( "b) an infinite number of solutions .
\n" ); document.write( "c) no solution.
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Algebra.Com's Answer #339758 by emargo19(101)\"\" \"About 
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a) only one solution ,(5,1) ****instead of (2,3)
\n" ); document.write( "Lets use point slope intercept equation
\n" ); document.write( "let's say the slope is -2.
\n" ); document.write( "So,
\n" ); document.write( "\"%28y-y1%29=m%28x-x1%29+\"
\n" ); document.write( "\"%28y-1%29=-2%28x-5%29\"
\n" ); document.write( "\"y-1=-2x%2B10\"
\n" ); document.write( "\"y=-2x%2B11\"----Eq1\r
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\n" ); document.write( "\n" ); document.write( "For next equation:
\n" ); document.write( "Lets use point slope intercept equation
\n" ); document.write( "let's say the slope is 2.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y-y1=m%28x-x1%29\"
\n" ); document.write( "\"y-1=2%28x-10%29\"
\n" ); document.write( "\"y=2x-9\" ----Eq2\r
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\n" ); document.write( "\n" ); document.write( "Next lets check\r
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\n" ); document.write( "\n" ); document.write( "Lets substitute
\n" ); document.write( "\"y=2x-9\" in eq 1
\n" ); document.write( "\"y=-2x%2B11\"\r
\n" ); document.write( "\n" ); document.write( "So,
\n" ); document.write( "\"2x-9=-2x%2B11\"
\n" ); document.write( "\"4x=11%2B9\"
\n" ); document.write( "\"4x=20\"
\n" ); document.write( "\"x=5\"\r
\n" ); document.write( "\n" ); document.write( "Next lets substitute x=5 in eq
\n" ); document.write( "\"y=2%285%29-9\"
\n" ); document.write( "\"y=10-9\"
\n" ); document.write( "\"y=1\"\r
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\n" ); document.write( "\n" ); document.write( "Therefore eqs are
\n" ); document.write( "\"y=-2x%2B11\"----Eq1
\n" ); document.write( "\"y=2x-9\" ----Eq2\r
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\n" ); document.write( "\n" ); document.write( "----------------------
\n" ); document.write( "For NO SOLUTION\r
\n" ); document.write( "\n" ); document.write( "REmember:
\n" ); document.write( "No solution happens when two graphs are parallel. It looks like this (0=7)
\n" ); document.write( "To make lines Paralel we have to have equal slopes.\r
\n" ); document.write( "\n" ); document.write( "Lets use the point slope equation
\n" ); document.write( "Lets choose points (3,2) and slope as 4.\r
\n" ); document.write( "\n" ); document.write( "\"y-y1=m%28x-x1%29\"
\n" ); document.write( "\"y-3=4%28x-2%29\"
\n" ); document.write( "\"y=4x-8%2B3\"
\n" ); document.write( "\"y=4x-5\" ----eq1\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Lets use the point slope equation again
\n" ); document.write( "This time lets choose points (2,1) and slope as 4.\r
\n" ); document.write( "\n" ); document.write( "\"y-y1=m%28x-x1%29\"
\n" ); document.write( "\"y-1=m%28x-2%29\"
\n" ); document.write( "\"y=4x-8%2B1\"
\n" ); document.write( "\"y=4x-7\" ----eq2\r
\n" ); document.write( "\n" ); document.write( "Lets check:
\n" ); document.write( "y=4x-5
\n" ); document.write( "y=4x-7
\n" ); document.write( "Substitute y=4x-7 in eq y=4x-5
\n" ); document.write( "\"4x-7=4x-5\"
\n" ); document.write( "\"4x-4x=-5%2B7\"
\n" ); document.write( "\"0=2\"\r
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\n" ); document.write( "\n" ); document.write( "c)infinite number of solutions
\n" ); document.write( "All that you need to do here is to write an equation and make a second equation a multiple
\n" ); document.write( "of the first equation. Example:
\n" ); document.write( ".
\n" ); document.write( "The first equation is y = 2x +1 ---eq1
\n" ); document.write( ".
\n" ); document.write( "The second equation is 2y = 4x + 2 ---eq2
\n" ); document.write( ".
\n" ); document.write( "This 2nd equ is just 2 times the 1st eq.
\n" ); document.write( " So this makes both eq the same they will have the same graph(1 line on the graph. So, these two eqns will have an infinite number of common
\n" ); document.write( "solns.\r
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