Please help. Calculate the area of the shaded region in each figure use 3.14 for π and round to the nearest 10th if necessary

Given this information, which expression must represent the value of b?

Asalesperson earns $320 per week plus 8% of her weekly sales. the expression representing her earnings is 320 + 0.08x. which of the following describes the sales necessary for the salesperson to earn at least $1000 in the one week?

Given the functions, f(x) = 2x^2 - 1 and g(x) = 5x, find f(g(x)) and g(f(