Which of the following statement is incorrect?  a. Closure property is true for subtraction of Rational numbers b. Commutative property is true for subtraction of Rational numbers c. Closure property is true for addition of Rational numbers d. Closure property is true for multiplication of Rational numbers​

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)