"x-intercept 5" means the point (5,0). 

Use the slope formula:



where (x1,y1) = (5,0)

and where (x2,y2) = (9,6)







Now use the point-slope formula:

y - y1 = m(x - x1)

where (x1,y1) = (5,0)

y - 0 = (x - 5)

y = (x - 5)



Edwin