What is the nth rule of the quadratic sequence 4,15,30,49,72,99,130

2(n²)+5n-3

Step-by-step explanation:

4,15,30,49,72,99,130

1st you find the difference between the numbers: (e.g. difference between 4 and 15 is 11)     11,15,19,23,27,31 Then you find the second difference between them.     4,4,4,4,4,4

If you divide the second difference by 2, you will get the value of a. 4 ÷ 2 = 2

So the first term of the nth term is 2n²

Then you have to do what do you do to get from 2n² to 4,15,30,49,72,99,130

3 3 6, because in every triangle the longer side is always shorter than the sum of the other two

0lz try yourself sorry for not answering