A. The value y-intercept represent in the context of the problem is 50.
B. The slope of the line is -10.
C. The equation to represent the line is y= -10x+50.
D. The number of customers in the restaurant at 8:30pm is 35.
<u>Step-by-step explanation:</u>
The equation of the line is given by y=mx+c.
y is the number of customers and x is the hours.
7.00 p.m. is considered as 0.
To find the slope m =
.
.
From the graph, choose two points. Let us take (0,50) and (4,10).

m=-10.
∴The equation can be written as y= -10x+c.
To find the y-intercept value c, substitute any point.
Let us substitute(0,50) for instance,
50=0+c.
c=50.
The equation for the given graph is y= -10x+50.
To find the customers at the restaurant at 8.30 pm.
we know that x=0 at 7.00 pm,
∴ x=1.5 can be considered as 8.30 pm.
Substitute x=1.5 in the line equation.
y= -10(1.5)+50.
y= -15-50.
y= 35.