Break apart ones to make a ten use this as a way to add 27+8

1c) the number 131 is a term in the sequence defined by the explicit rule f(n)=5n-4. which term in the sequence is 131? 2a) write the first four terms of the function f(n)=n^2-1 2b) what is the 10th term of the sequence defined by the explicit rule f(n)=n^2-1 2c) the number 224 is a term in the sequence defined by the explicit rule f(n)=n^2-1. which term in the sequence is 224?

Complete the solution of the equation. find the value of y when x equals to 6 4x+y=20

Asap! i'm not good math and i'm lost.