Hello please help me with this expand question 3(p+5)-3(p+2) and please simplify

An arc subtends a central angle measuring 7pi/4 radians what fraction of the circumference is this arc?

The base of a triangle is 8 1 3 meters and the height of the triangle is the fourth root of 16 meters meters. what is the area of the triangle?

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.