document.write( "Question 110604: using the two equations below, solve for x and y using three different methods, substituion, addition and graphing.\r
\n" ); document.write( "\n" ); document.write( "-2x+3y=6
\n" ); document.write( "3x-5y=-11
\n" ); document.write( "

Algebra.Com's Answer #80825 by ankor@dixie-net.com(22740)\"\" \"About 
You can put this solution on YOUR website!
using the two equations below, solve for x and y using three different methods, substitution, addition and graphing.
\n" ); document.write( "-2x + 3y = 6
\n" ); document.write( " 3x - 5y =-11
\n" ); document.write( ":
\n" ); document.write( "Substitution:
\n" ); document.write( "Rearrange the 1st equation to be used for subsitution:
\n" ); document.write( "3y = 2x + 6
\n" ); document.write( "y = \"2%2F3\"x + \"6%2F3\"; divided equation by 3
\n" ); document.write( "y = \"2%2F3\"x + 2
\n" ); document.write( ":
\n" ); document.write( "Substitute (\"2%2F3\"x + 2) for y in the 2nd equation:
\n" ); document.write( "3x - 5(\"2%2F3\"x + 2) = -11
\n" ); document.write( ":
\n" ); document.write( "3x - \"10%2F3\"x - 10 = -11
\n" ); document.write( ";
\n" ); document.write( "\"9%2F3\"x - \"10%2F3\"x = -11 + 10
\n" ); document.write( ":
\n" ); document.write( "-\"1%2F3\"x = -1
\n" ); document.write( ":
\n" ); document.write( "\"1%2F3\"x = 1; multiplied by -1 to get rid of the negatives
\n" ); document.write( ":
\n" ); document.write( "x = 3; Multiplied by 3 to get rid of the fraction
\n" ); document.write( ":
\n" ); document.write( "Find y using the y = \"2%2F3\"x + 2
\n" ); document.write( "y = \"2%2F3\"3 + 2
\n" ); document.write( "y = 2 + 2
\n" ); document.write( "y = 4
\n" ); document.write( ":
\n" ); document.write( "Our solution x = 3; y = 4
\n" ); document.write( ":
\n" ); document.write( "Substitute for x and y in the 2nd equation to confirm our solutions:
\n" ); document.write( "3x - 5y =-11
\n" ); document.write( ":
\n" ); document.write( "3(3) - 5(4) =
\n" ); document.write( "9 - 20 = -11
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Elimination:
\n" ); document.write( "-2x + 3y = 6
\n" ); document.write( " 3x - 5y =-11
\n" ); document.write( ":
\n" ); document.write( "Multiply the 1st equation by 3 and the 2nd equation by 2:
\n" ); document.write( "-6x + 9y = 18
\n" ); document.write( "+6x -10y = -22
\n" ); document.write( "---------------adding eliminates x, find y:
\n" ); document.write( "0x - 1y = -4
\n" ); document.write( "y = +4
\n" ); document.write( "Find x just like we did before using substitution for y in either equation
\n" ); document.write( ":
\n" ); document.write( "To graph this:
\n" ); document.write( "y = \"2%2F3\"x + 2; from above:
\n" ); document.write( "and
\n" ); document.write( " 3x - 5y =-11
\n" ); document.write( "-5y = - 3x - 11
\n" ); document.write( "5y = 3x + 11; multiplied by -1 to get rid of all those negatives
\n" ); document.write( "y = \"3%2F5\"x + \"11%2F5\"
\n" ); document.write( ":
\n" ); document.write( "Plot these to equations, should look like this
\n" ); document.write( "\"+graph%28+500%2C+500%2C+-6%2C+8%2C+-2%2C+5%2C+%282%2F3%29x+%2B2%2C+.6x%2B%2811%2F5%29%29+\"
\n" ); document.write( ":
\n" ); document.write( "Not very clear but they should intersect at x=3, y=4
\n" ); document.write( ":
\n" ); document.write( "How about this? Did it explain these three methods to you?
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