The altitude of an airplane is decreasing at a rate 42 feet per second what is the change in altitude of the airplane over a period of 16 seconds

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.

For the quadratic function [tex]y=(x+4)^2-1[/tex] , do the following: a) rewrite the function in the standard form, b) rewrite the function in intercept form, c) find the vertex, d) find the y-intercept, e) find the x-intercepts.

Step by step explanation pls for 10 pts the length of a rectangular board is 3 feet less than twice its width. a second rectangular board is such that each of its dimensions is the reciprocal of the corresponding dimensions of the first rectangular board. if the perimeter of the second board is one-fifth the perimeter of the first, what is the perimeter of the first rectangular board?