Question

解方程：N(N+2)=168

求快

Answer 1

解：
N(N+2)=168
N²+2N=168
N²+2N-168=0
(N+14)(N-12)=0
N+14=0, 或N-12=0
∴N1＝-14，N2＝12

Answer 2

N(N＋2)=168
N²＋2N－168=0
(N－12)(N＋14)=0
N=12或N=－14

Answer 3

n²+2n-168=0
(n-14)(n+16)=0
n=14,n=-16

Answer 4

N^2+2N-168=0
(N+14)(N-12)=0
N=-14或12

Answer 5

N^2+2N-168=0

能够解得（N+1）^2=169
N=±13-1

N=12 或者N=-14

Answer 6

N(N+2)=168
N^2+2N-168=0
(N-12)(N+14)=0
N =12,N=-14