The equation of the line L1 is y = 3x – 2 The equation of the line L2 is 3y – 9x + 5 = 0 Show that these two lines are parallel.

Two lines are parallel if they have the same gradient. This can be found by looking at the coefficient of x. When the equation is written in the form y=ax+b, with b a constant, the gradient of the line would be a. So for the L1 the gradient is 3. So we want to get L2 in this form as well we rearrange L2, to 3y = 9x - 5, and then divide by 3 to get y = 3x -5/3. So the gradient of L2 is also 3 and therefore both lines are parallel.

JS

Related Further Mathematics GCSE answers

All answers ▸

Show that 2cos^2(x) = 2 - 2sin^2(x) and hence solve 2cos^2(x) + 3sin(x) = 3 for 0<x<180


How can I find the equation of a straight line on a graph?


The equation 3x^2 – 5x + 4 = 0 has roots P and Q, find a quadratic equation with the roots (P + 1/2Q) and (Q + 1/2P)


f(x) = 3x^3 – x^2 – 20x – 12 (a) Use the factor theorem to show that (3x + 2) is a factor of f(x). [2 marks] (b) Factorise f(x) fully. [3 marks]