"Find the missing side" , its due today.
Please help me on my homework.​

Twice the sum of a number and 4 is equal to three times the difference of the number and 7. find the number.

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.

Another type of subtraction equation is 16-b=7. explain how you would sole this equation then solve it.