Answer:
The value of a is 8
Step-by-step explanation:
If the three lines are collinear, they all lie on the same line
So let us have the equation of a line that passes through the known ends
the slope will be;
m = (6-2)/(3 + 5) = 4/8 = 1/2
The general form is;
y = mx + b
so, we have
y = 1/2x + b
To get b, we use any of the two known points
6 = 3/2 + b
b = 6-3/2
b = (12-3)/2 = 9/2
So the equation of the line is;
y = 1/2x + 9/2
Multiply through by 2
2y = x + 9
So for the point , to get a , we have that
2(a) = 7 + 9
2a = 16
a = 16/2
a = 8
