Rewrite the expression -3(x-4)^2 in the form ax^2 + bx + c

Avegetable garden and a surrounding path are shaped like a square together are 12 ft wide. the path is 1 feet wide. if one bag of gravel covers 8 square feet, how manu bags are needed to cover the path? round your answers to the nearest tenth.

How to do this , and can some one explain

How can you construct perpendicular lines and prove theorems about perpendicular lines