What’s the answer

Question

Which of the following is an equation of the line that is parallel to y= -8x+1 and passes through (2,-6) in the standard (x,y) coordinate plane?

Answer 1

There are 2 ways to do this. Remember that parallel lines have the same slope.

1. Solve for b.

y = mx + b

-6 = -8(2) + b

-6 = - 16 + b

b = 10

y = -8x + 10

2. Use the point-slope formula.

y - y₁ = m(x - x₁)

y - (-6) = -8(x - 2)

y + 6 = -8x + 16

y = -8x + 10

Answer 2

y=-8x+1 is the equation of a line in y=mx+b form, where m is the slope, so here the slope = -8.

Parallel lines have the same slope so the equation of a line parallel to y=-8x+1 has slope -8 and that line has the equation y=-8x + b.

We know that line passes through (2,-6), so to solve for b, we plug (2,-6) into the latter equation.