The given equation of the line is 3x + 4y = 10.
Slope of the line =
The required line is parallel to the line 3x + 4y = 10 and we know that parallel lines have equal slopes.
Hence, slope of the required line, m = and point (2, 1) lies on the required line.
So, the point slope form of the equation is
y y1 = m (x x1)
⇒ y ( 1) = (x 2)
⇒ y + 1 = (x 2)
⇒ 4(y + 1) = 3 (x 2)
⇒ 4y + 4 = 3x + 6
∴ 3x + 4y 2 = 0, which is the required equation.