I believe that X would be -2.47619.
First you distribute the -1 in front of the parenthesis. Then distribute the 8 outside of the bracts. And finally just solve for X by combing like terms.
All i know is that the equation of a straight line is y=mx+c .......where m= gradient and c= the y intercept
3,000 y / 15 m
9,000 f / 15 m
X f / 6 m = 9,000 f / 15 m
Cross multiply
3,600 feet
First, you factor and simplify (respectively) the numerator and denominator. Your equation becomes:

Notice, there is a (x + 7) on both the top and the bottom. Because of this, they cancel each other out. What is left is your answer:
Point slope form is just a point and the slope written in the form y-y1 =m (x-x1).
Where x1 and y1 (should be subscripts) are (x1,y1) the point you are given.
So in this case all you must do is plug in the given values:
( y-y1 ) = m ( x-x1 )
( y-4. ) = -1 ( x-2 )
This being your answer
I hope this helps!!