Question 941041
 a * b = a^2 + ab 
2 * x = 0 
  2*x  = 2^2+2*x
  0= 4+2x
   subtract 4 on both sides
 0-4= 4+2x-4
   -4 = 2x
 divide with 2 on both sides
 {{{ -4/4 = 2x/2}}}
   -2= x
 hence x= -2