Prove a quadrilateral with vertices g(1,-1), h(5,1), i(4,3), j(0,1) is a rectangle

parallelogram method:
rectangle method:

i need understanding how to prove it's a rectangle

Which system of linear inequalities is represented by the graph? !

Aheated piece of metal cools according to the function c(x) = (.5)x ? 7, where x is measured in hours. a device is added that aids in cooling according to the function h(x) = ? x ? 2. what will be the temperature of the metal after two hours?

What is the slope of the equation y =