How many marbles do you need to be able to arrange them into the shape of an equilateral triangle with 75 rows

The first five terms of a linear sequence are given below. 7 , 12 , 17, 22 , 27 , what is the next term of the sequence?

How many solutions does the nonlinear system of equations graphed below have?

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.