document.write( "Question 209077: find the minumum value of f(x,y)=2x-y+2 for the polygonal convex set determined by this system of inequalities:x>=1, x<=3, y>=0, 1/2x + y<=5.\r
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document.write( "A)0\r
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document.write( "B)-3\r
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document.write( "C)3\r
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document.write( "D)-0.5 \n" );
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Algebra.Com's Answer #158173 by RAY100(1637)![]() ![]() ![]() You can put this solution on YOUR website! To best visualize this problem, please draw on a standard x-y coordinate system, the area of concern. \n" ); document.write( ". \n" ); document.write( "(1) x>=1,,,, to the right of a vertical line at x=1 \n" ); document.write( ". \n" ); document.write( "(2) x<=3,,,,,to the left of a vertical line at x=3 \n" ); document.write( ". \n" ); document.write( "(3) y>=0,,,,,,,above a horizontal line at y=0 \n" ); document.write( ". \n" ); document.write( "(4) (x/2) +y <= 5,,,,,below a line from (1,4.5) to (3,3.5) \n" ); document.write( ". \n" ); document.write( "Now, to find the min of f(x,y) = 2x -y +2,,,let's look at the corners of the area of concern,,,by just substituting coordinate values in function \n" ); document.write( ". \n" ); document.write( "(1,0),,,,,f(x,y) = 4 \n" ); document.write( ". \n" ); document.write( "(1, 4.5),,,f(x,y) = -.5 \n" ); document.write( ". \n" ); document.write( "(3,3.5),,,,f(x,y) = .5 \n" ); document.write( ". \n" ); document.write( "(3,0),,,,,f(x,y) = 8 \n" ); document.write( ". \n" ); document.write( ". \n" ); document.write( ". \n" ); document.write( "It appears to be a min at -.5, which is answer (D) \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( " |