## Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

We are given the following equation: $$M=-\frac{1}{2}t^2+\frac{5}{2}t$$ Plugging in 2 for M, we find: $$2=-\frac{1}{2}t^2+\frac{5}{2}t \\ -t^2+5t-4=0 \\ t_{1,\:2}=\frac{-5\pm \sqrt{5^2-4\left(-1\right)\left(-4\right)}}{2\left(-1\right)} \\ t=1,4$$