Im having trouble with the first question :( please help

Quadrilateral wxyz is on a coordinate plane. segment yz is on the line x+y=7 and segment xw is on the line x+y=3. which statement proves how segments yz and xw are related

Let the closed interval [a , b] be the domain of function f. the domain of f(x - 3) is given by (a) the open interval (a , b) (b) the closed interval [a , b] (c) the closed interval [a - 3 , b - 3] (d) the closed interval [a + 3 , b + 3]

What is the slope of the line shown below?