Which of the following functions describes the sequence 1, 3, 7, 15, 31, 63, 127, … ?

A. f(1) = 1,f(n) = f(n − 1) + n for n > 1.
B. f(1) = 1,f(n) = 2n + 1 for n > 1.
C. f(1) = 1,f(n) = f(n − 1) + 2(n − 1) for n > 1.
D. f(1) = 1,f(n) = 2f(n − 1) + 1 for n > 1.

Create a real-life situation and create a system and show how it might be modeled algebraically with a system of equations (or inequalities) show all work include a few sentences explaining the situation, your variables of choice and what each represents, and how you would set it up and solve it algebraically. !

In factoring by grouping, what would you have for step 3 for the following? step 1: x^3 +5x^2 +4x+20 step 2: x^2 (x+5)+4(x+5) step 3: ?

David is spreading mulch on a triangular area of his flower bed. the coordinates of the vertices of the area are (1, 3), (9, 3), and (4, 6). what is the area of the triangle if each square has an area of 3 square feet?