M and line n are parallel. What is the value of x? If m=3x-10 and n=5x+30

Anyone know? is appreciated! will mark brainliest if correct!

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 0 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)

Last one and the bottom answer choice is y=(x-4)^2+1 you guys!