What is the solution to this system of equations?

Describe the possible echelon forms of the standard matrix for a linear transformation t where t: set of real numbers is onto.

Iwant to know what 3g+5h+4g-2h is my teacher is too selfish to tell us

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)