what is the equation of the line that is perpendicular and passes through the points (4,-6) and the equation that is parallel with the points (4,-6)

How do you use the elimination method for this question? explain, because i really want to understand!

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 a. at what time does the particle reverse direction? b. when is the displacement positive? (round one decimal place and answer in interval notation) c. when is the displacement negative? (round one decimal place and answer in interval notation) d. when is the particle’s acceleration positive? (round one decimal place and answer in interval notation) e. when is the particle’s acceleration negative? (round one decimal place and answer in interval notation)

The polynomial 10x3 + 35x2 - 4x - 14 is factored by grouping. 10x3 + 35x2 - 4x - 14 5x )-20 what is the common factor that is missing from both sets of parentheses?