document.write( "Question 181721: Use Substitution to solve each system of equations. If the system does not have exactly one solution, state if it has no solution or infinitely many solutions. x-5y=36 and 2x+y=-16 \n" ); document.write( "
Algebra.Com's Answer #136567 by eperette(173)\"\" \"About 
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x - 5y = 36
\n" ); document.write( "2x + y = -16\r
\n" ); document.write( "\n" ); document.write( "before we can use the substitution method, we should have an x= or y= equation....so \r
\n" ); document.write( "\n" ); document.write( "x - 5y = 36
\n" ); document.write( "x-5y+5y=36+5y
\n" ); document.write( "x+0 = 36 + 5y
\n" ); document.write( "x= 5y + 36\r
\n" ); document.write( "\n" ); document.write( "Now we will substitute the right part of this equation into the x value in the second equation\r
\n" ); document.write( "\n" ); document.write( "2x + y = -16
\n" ); document.write( "2(5y + 36) + y =-16
\n" ); document.write( "2(5y) + 2(36) + y = -16
\n" ); document.write( "10y + 72 + y = -16
\n" ); document.write( "11y + 72 = -16
\n" ); document.write( "11y+72-72=-16-72
\n" ); document.write( "11y+0=-88
\n" ); document.write( "11y/11=-88/11
\n" ); document.write( "y=-8\r
\n" ); document.write( "\n" ); document.write( "Now to find x, we will substitute y=-8 into first equation\r
\n" ); document.write( "\n" ); document.write( "x = 5y + 36
\n" ); document.write( "x = 5(-8) + 36
\n" ); document.write( "x = -40 + 36
\n" ); document.write( "x = -4\r
\n" ); document.write( "\n" ); document.write( "So my answer is (-4, -8)...\r
\n" ); document.write( "\n" ); document.write( "Lets check:
\n" ); document.write( "x-5y=36
\n" ); document.write( "(-4)-5(-8)
\n" ); document.write( "-4 + 40
\n" ); document.write( "36 right
\n" ); document.write( "AND
\n" ); document.write( "2x+y=-16
\n" ); document.write( "2(-4)+(-8)
\n" ); document.write( "-8 -8
\n" ); document.write( "-16 right
\n" ); document.write( " \n" ); document.write( "
\n" );