The graph shows four separate equations all representing the line, but written out in different ways. The easiest way to determine which does not represent the line is by assigning values for x and y, and this chosen ordered pair must satisfy only the correct equations.
Therefore, using the value of x to be equal to 2,
When x = 2,
y = 7/2(2 + 6)
y = 7/2(8)
y = 28
For equation B, when x = 2
y = 7/2 (2) + 21
y = 7 + 21
y = 28
For equation C, when x = 2,
y - 7 = 7/2 (2 + 4)
y - 7 = 7/2 (6)
y - 7 = 21
y = 21 + 7
y = 28
For equation D, when x = 2
y + 5 = 7/2 (2 + 8)
y + 5 = 7/2 (10)
y + 8 = 35
y = 35-8
y = 27
Only equation D does not satisfy the ordered pair (2, 28), hence the line is not represented by equation D