Equation of straight line with slope 3 and passing through the point (30,40) is (y−40)=3(x−30) ⇒‌‌y−40=3x−90 ⇒‌‌3x−y=50 ‌
x
(‌
50
3
)
+‌
y
(−50)
=1.....(i) and equation of straight line with slope 6 and passing through the point (30,40) is (y−40)=6(x−30) ⇒‌‌y−40=6x−180 ⇒6x−y=140 ⇒‌
x
(‌
70
3
)
+‌
y
(−140)
=1......(ii) ∴ The difference between the y -intercepts of the straight lines