Question 932991
Let x = the number

Two times a number plus the square of the number equals 48.
    2x+x^2=48
  x^2+2x-48=0
(x+8)(x-6)=0

x=-8
or
x=6

Substitute x with -8
2(-8)+ (-8)^2=48
     -16 + 64=48
           48=48

Substitute x with 6
  2(6)+ (6)^2=48
      12 + 36=48
           48=48

The number is either -8 or 6.