Under what conditions can the t-distribution be correctly employed to test the difference between two population means?

Anna is no more than 3 years older than 2 times jamie’s age. jamie is at least 14 and anna is at most 35. which system of linear inequalities can be used to find the possible ages of anna, a, and jamie, j?

Which is the equation of an ellipse with directrices at x = ±4 and foci at (2, 0) and (−2, 0)?

Prove that the value of the expression 7^8–7^7+7^6 is divisible by 43.