Please help.
Algebra.

Let the mean of the population be 38 instances of from 6" - 9" hatchings per nest, and let the standard deviation of the mean be 3. what sample mean would have a confidence level of 95% or a 2.5% margin of error?

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15

Secant be and cf intersect at point d inside a what is the measure of cde