Answer:
n= -1/2 & 1/2
Explanation:
first factor out the greatest common factor which is 7
7(4n² - 1)
Then factor it further inside the parenthesis
7(2n+1)(2n-1) (if you distribute you'll see that 7(2n+1)(2n-1)=7(4n² - 1) )
Then you set each part of the equation equal to 0
2n+1=0
2n= -1
n= -1/2
2n-1=0
2n= 1
n= 1/2