Can you guys help, plz i dont understand it

Module 10 coordinate proof using slope and distance answers is quadrilateral abcd a parallelogram? explain how you know.

Scrub a dub toothbrushes are $4.00 each. there is a 10% discount, but there is also a 6% sales tax after the discount is applied. what is the new price after tax? round to the nearest penny

For g(x) = 5x - 3 and h(x) = [tex]\sqrt{x}[/tex], find (g · h)(4)