[2 x 2(2 + 1)^2= please help

Select all the correct answers. what is 221,000,000,000,000,000,000 expressed in scientific notation?

Complete the table for different values of x in the polynomial expression -7x2 + 32x + 240. then, determine the optimal price that the taco truck should sell its tacos for. assume whole dollar amounts for the tacos.

A33 gram sample of a substance that's used to detect explosives has a k-value of 0.1473. n = noekt no = initial mass (at time t = 0) n = mass at time t k = a positive constant that depends on the substance itself and on the units used to measure time t = time, in days