Five sandwiches and four drinks cost £20. Two sandwiches and five drinks cost £8. Find the cost of one sandwich.

What is this equation in point-slope form?

Solve the system of equations. y= 2x y= x^2 - 15

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)