Solution
Let us test each of the coordinates points
at ( 2, 4 )
at x=2
No agreement with the y-coordinate
Let us test the second coordinate point ( 4 , 7 )
at x = 4
No agreement with the y-coordinate
Let us test the third coordinate point (5, 12 )
at x= 5
No agrement with the y-coordinate
Based on the information you have provided in the question , y= - 2.5x - 1.5 is not a correct regression equation for the line .