Q. 2. Solve the below LP using SIMPLEX method. Maximize subject to −x1−x2+4x3x1+x2+2x3≤9x1+x2−x3≤2−x1+x2+x3≤4x1,x2,x3≥0.
Set up simplex tableau: Set up the initial simplex tableau. Introduce slack variables s1, s2, and s3 for the constraints to turn inequalities into equations.
Update tableau after row operations: Identify the entering variable. It's the one with the most negative coefficient in the objective function row. Here, it's x3.
Identify new entering variable: Identify the leaving variable using the minimum ratio test. Divide the RHS by the corresponding coefficients of x3 in the constraint rows.
Update tableau after row operations: The ratios are 29 for s1, undefined for s2 (since −1 is negative), and 14 for s3. The smallest positive ratio is 4, so s3 will leave.
Update tableau after row operations: The ratios are 29 for s1, undefined for s2 (since −1 is negative), and 14 for s3. The smallest positive ratio is 4, so s3 will leave.Perform row operations to make x3 a basic variable and update the tableau.
Update tableau after row operations: The ratios are 29 for s1, undefined for s2 (since −1 is negative), and 14 for s3. The smallest positive ratio is 4, so s3 will leave.Perform row operations to make x3 a basic variable and update the tableau.The updated simplex tableau after making x3 a basic variable is:| | s10 | s11 | x3 | s1 | s2 | s3 | RHS ||---|-------|-------|-------|-------|-------|-------|-----|| s16 | s17 | s18 | s19 | s19 | s19 | 4 | s23 || s1 | s25 | −1 | s19 | s28 | s19 | −10 | s28 || s2 | −13 | s19 | s19 | s19 | s28 | s28 | −19 || x3 | −1 | s28 | s28 | s19 | s19 | s28 | 4 |
Update tableau after row operations: The ratios are 29 for s1, undefined for s2 (since −1 is negative), and 14 for s3. The smallest positive ratio is 4, so s3 will leave.Perform row operations to make x3 a basic variable and update the tableau.The updated simplex tableau after making x3 a basic variable is:| | s10 | s11 | x3 | s1 | s2 | s3 | RHS ||---|-------|-------|-------|-------|-------|-------|-----|| s16 | s17 | s18 | s19 | s19 | s19 | 4 | s23 || s1 | s25 | −1 | s19 | s28 | s19 | −10 | s28 || s2 | −13 | s19 | s19 | s19 | s28 | s28 | −19 || x3 | −1 | s28 | s28 | s19 | s19 | s28 | 4 |Identify the new entering variable. It's s10 with the most positive coefficient in the objective function row.
Update tableau after row operations: The ratios are 29 for s1, undefined for s2 (since −1 is negative), and 14 for s3. The smallest positive ratio is 4, so s3 will leave.Perform row operations to make x3 a basic variable and update the tableau.The updated simplex tableau after making x3 a basic variable is:| | s10 | s11 | x3 | s1 | s2 | s3 | RHS ||---|-------|-------|-------|-------|-------|-------|-----|| s16 | s17 | s18 | s19 | s19 | s19 | 4 | s23 || s1 | s25 | −1 | s19 | s28 | s19 | −10 | s28 || s2 | −13 | s19 | s19 | s19 | s28 | s28 | −19 || x3 | −1 | s28 | s28 | s19 | s19 | s28 | 4 |Identify the new entering variable. It's s10 with the most positive coefficient in the objective function row.Perform the minimum ratio test again for s10. The ratios are s30 for s1 and s32 for s2. The smallest positive ratio is s30, so s1 will leave.
Update tableau after row operations: The ratios are 29 for s1, undefined for s2 (since −1 is negative), and 14 for s3. The smallest positive ratio is 4, so s3 will leave.Perform row operations to make x3 a basic variable and update the tableau.The updated simplex tableau after making x3 a basic variable is:| | s10 | s11 | x3 | s1 | s2 | s3 | RHS ||---|-------|-------|-------|-------|-------|-------|-----|| s16 | s17 | s18 | s19 | s19 | s19 | 4 | s23 || s1 | s25 | −1 | s19 | s28 | s19 | −10 | s28 || s2 | −13 | s19 | s19 | s19 | s28 | s28 | −19 || x3 | −1 | s28 | s28 | s19 | s19 | s28 | 4 |Identify the new entering variable. It's s10 with the most positive coefficient in the objective function row.Perform the minimum ratio test again for s10. The ratios are s30 for s1 and s32 for s2. The smallest positive ratio is s30, so s1 will leave.Perform row operations to make s10 a basic variable and update the tableau.
Update tableau after row operations: The ratios are 29 for s1, undefined for s2 (since −1 is negative), and 14 for s3. The smallest positive ratio is 4, so s3 will leave.Perform row operations to make x3 a basic variable and update the tableau.The updated simplex tableau after making x3 a basic variable is:| | s10 | s11 | x3 | s1 | s2 | s3 | RHS ||---|-----|-----|-----|-----|-----|-----|-----|| s16 | s17 | s18 | s19 | s19 | s19 | 4 | s23 || s1 | s25 | −1 | s19 | s28 | s19 | −10 | s28 || s2 | −13 | s19 | s19 | s19 | s28 | s28 | −19 || x3 | −1 | s28 | s28 | s19 | s19 | s28 | 4 |Identify the new entering variable. It's s10 with the most positive coefficient in the objective function row.Perform the minimum ratio test again for s10. The ratios are s30 for s1 and s32 for s2. The smallest positive ratio is s30, so s1 will leave.Perform row operations to make s10 a basic variable and update the tableau.The updated simplex tableau after making s10 a basic variable is:| | s10 | s11 | x3 | s1 | s2 | s3 | RHS ||---|-----|-----|-----|-----|-----|-----|-----|| s16 | s19 | 46 | s19 | s17 | s19 | s28 | s31 || s10 | s28 | s34 | s19 | s36 | s19 | s38 | s36 || s2 | s19 | x32 | s19 | s38 | s28 | x36 | x37 || x3 | s19 | x32 | s28 | s36 | s19 | s36 | x35 |
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