document.write( "Question 4822: what is the solution of x+y=4 and 2x-y=-5 \n" ); document.write( "
Algebra.Com's Answer #2322 by Abbey(339)\"\" \"About 
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This problem is perfect for the substitution method:\r
\n" ); document.write( "\n" ); document.write( "Rewrite x + y = 4 as
\n" ); document.write( "y = 4-x by subtracting x from both sides of the equation.\r
\n" ); document.write( "\n" ); document.write( "then use this (4-x) in the second equation for y:
\n" ); document.write( "2x-y=-5 as
\n" ); document.write( "2x-(4-x)=-5\r
\n" ); document.write( "\n" ); document.write( "Clear the parentheses:
\n" ); document.write( "2x-4+x=-5\r
\n" ); document.write( "\n" ); document.write( "Combine like terms:
\n" ); document.write( "3x-4=-5\r
\n" ); document.write( "\n" ); document.write( "3x-4+4=-5+4
\n" ); document.write( "3x=-1\r
\n" ); document.write( "\n" ); document.write( "Divide both sides by 3 to isolate the variable:
\n" ); document.write( "x=-1/3\r
\n" ); document.write( "\n" ); document.write( "By putting the x value back into either equation:
\n" ); document.write( "-1/3+y=4
\n" ); document.write( "y=4 2/3\r
\n" ); document.write( "\n" ); document.write( "After putting both x and y into the equations to verify the results:
\n" ); document.write( "-1/3 + 4 1/3 = 4
\n" ); document.write( "2(-1/3)-4 1/3 = -5\r
\n" ); document.write( "\n" ); document.write( "The solution set is:
\n" ); document.write( "(-1/3,4 1/3)
\n" ); document.write( " \n" ); document.write( "
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