Find the equation of the line which is parallel to y=8x-4 and passes through (3, 12)

Question

Equation which is parallel and contains a negative.

Answer 1

Two lines that are parallel have the same slope, which in this case is 8.

In slope-intercept form the equation is y-12=8(x-3).

That’s the same as y=8x-24+12=8x-12, so y=8x-12 is the equation of the parallel line.

Answer 2

The gradient (or slope) of the parallel line will be the same, which is 8. We know the values of x and y so if we put those in the equation for a straight line, y=mx+c, we get 12= 8(3)+c. 8*3 is 24 so 12=24+c, if we takeaway 24 from both sides we are left with c=-12 so the equation of the parallel line is y=8x-12.