Question 199210
Let  n = number
.
2 n^2 = 8 n
.
2 n^2 -8 n =0
,
factor
.
2n ( n-4) = 0
.
use  zero  property
.
2n = 0, n=0,,,,,,,,,n-4 = 0,,,  n= 4
.
check
n=0, 2* 0^2 =8*0,,,,ok
n=4, 2* 4^2 =8 * 4,,,  32=32,,,,ok