Eighteen is 40% of what number? a. 75 b. 45 c. 22 d. 18

Anyone know? is appreciated! will mark brainliest if correct!

Determine whether the points (–3,–6) and (2,–8) are in the solution set of the system of inequalities below. x ? –3 y < 5? 3x + 2 a. the point (–3,–6) is not in the solution set, and the point (2,–8) is in the solution set. b. neither of the points is in the solution set. c. the point (–3,–6) is in the solution set, and the point (2,–8) is not in the solution set. d. both points are in the solution set.

Determine the difference: 3.2 × 1010 – 1.1 × 1010. write your answer in scientific notation.