Amaths teacher bought 40 calculators at $8.20 each and a number of other calculators costing $2.95 each. in all she spent$387. how many of the cheaper calculators did she buy?

In which form is the following function written? y = - 2(x – 3)(x + 5)

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)

Ling is using fraction strips to add 2/3 and 7/12's the sum is one whole plus how many twelves?