Answer:
A
Step-by-step explanation:
By vertical line test, if you draw any vertical line, except for A, all graph meet at more than two points. So, graph A represents y as a function of x.
h
X>50
X>-51
6+x>56
56+x>5
separate the equation into different equations by the sign
I) 6+x>56
x>56-6
x>50
ii) 56+x>5
x>5-56
x>-51