The graph of an absolute value function f(x) = a|x| includes the point (1, 6). Another point of the graph is ( , 6). The value of a is (8.3 points)
A.
6
B.
-6
C.
-1
D.
1

How to solve it and what thw answer is

Iam trying to solve a linear equation for the shoe size of someone 84" tall taking into consideration example 1 is 69" tall with a shoe size of 9 and example 2 is 72 inches tall with a shoe size of 11. i understand that the equation should be y=mx+b and that on the graph the answer is (3,2) but i just don't understand how to create the equation to solve for 84-inches and 60-inches tall questions. after two days, i need .

Asquare parking lot has 6,400 square meters what is the length in meters