The sum of two numbers is -1. when twice the first number and four times the second number are added the sum is -10.what are the two numbers

How to determine whether two known pairs of points are on the same line.

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.

The collection of beautiful oil paintings currently on display at an art gallery well defined; set not well defined; not a set