1) Calculate the gradient of the line joining two points here.
2) Calculate the equation of the line through 2 given points here.
3) Calculate the midpoints and lengths of lines here.
4) Practice calculating parallel and perpendicular lines here.
5) Practice tax, monthly cost, supply demand questions here.
For Linear Programming, you need simultaneous equations. Practice here.
Basic Linear Programming Q1 here.
Basic Linear Programming Q2, here.
Application question 1, building on a plot of land, here.
Application question 2, building a play park, here.
Application question 3, designing cinema seating, here.
Application question 4, designing a garden, here.