Question

A line passes through the origin and has a slope of 4. What is the equation of the line that is parallel to the first line and passes through the point (1, –2)?

Answer 1

y = mx + b, but since it goes through te origine, then b =0 and the equation becomes: y = mx. To calculate m, replace x and y by their respective values in (1,-2),

-2 = m(1) . So m = -2 and y = -2x becomes the equation requested