Im trying to raise up my grade help plz

Iq scores for adults age 20 to 34 years are normally distributed according to n(120, 20). in what range does the middle 68% of people in this group score on the test?

1. what expression would be the same as 6x+x+0 2. find the prime factorization of 60 3. write the expression for 6 + x in words.

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?