What are the differences between corner point method and isoprofit line method? b$)(4)$for linear programmes, state why.$-$X; $2$X$2-$ X$31004$X$1-4$X$2=55$X$,-$ X$\}-4$X$3202/$X$,3$X$2$ X$3220$Xi X$210$X$3=60$vil$4$X$,4$X$2$ XiX$2$ $$25$c$)$Give a brief explanation on each type of problem variation in transportation and how to solve$(8)$d$)$ What are the steps in determining the initial basic feasible solution in linear programming simplex method before you can start the simplex method? In finding the optimum solution, how do you test for optimality?