Question

2(2n+1)^2-8(n+1)(n-1)=42

Answer 1

$2(4 {n}^{2} + 4n + 1) - 8( {n}^{2} - 1) = 42 \ 8 {n}^{2} + 8n + 2 - 8 {n}^{2} + 8 = 42 \ 8n + 10 = 42 \ 8n = 42 - 10 \ 8n = 32 \ n = frac{32}{8} \ n = 4$

Answer 2

2(4n + 5) = 42

8n + 10 = 42

8n = 32

n = 4