If c(x) = 4x – 2 and d(x) = x2 + 5x, what is (c circle d) (x)? 4x3 + 18x2 – 10x
x2 + 9x – 2
16x2 + 4x – 6
4x2 + 20x – 2

I'm terrible at math any here is appreciated.

"you know, playing tennis is healthier than watching a tennis match on television," katya remarked to her couch potato brother. in this sentence, healthier is a/an a. superlative. b. comparative. c. positive form. d. adverb.

Afactory makes propeller drive shafts for ships. a quality assurance engineer at the factory needs to estimate the true mean length of the shafts. she randomly selects four drive shafts made at the factory, measures their lengths, and finds their sample mean to be 1000 mm. the lengths are known to follow a normal distribution whose standard deviation is 2 mm. calculate a 95% confidence interval for the true mean length of the shafts. input your answers for the margin of error, lower bound, and upper bound.