The distance between the intercepts of both lines is 2 units
The equation of a line in slope intercept form is:

Where:
slope
y intercept
For the first line, we have:
---- the slope
So, the equation of the first line is:

For the second line, we have:
--- the slope
So, the equation of the second line is:

Both lines intersect at (10,15) means that (10,15) is a common solution to the equation of both lines
i.e.

Substitute these values in the first equation and solve for b





So, the equation of the first line is

Repeat the same process for the second line





So, the equation of the second line is

The x intercept is when 
So, we substitute 0 for y and solve for x in the equations of both lines
For line 1


---- Collect like terms
--- Divide both sides by 3
The x intercept of line 1 is 5
For line 2


--- Collect like terms
-- Divide both sides by 5
The x intercept of line 2 is 7
The distance (d) between both is the difference in the calculated intercepts:

