Which equation is related to  ? x  + 10 =  x2  +  x  + 1x  + 10 =  x2  + 2x  + 1x  + 10 =  x2  + 1x  + 10 =  x2  – 1

Instructions here are incomplete / unclear.  

However, as speculation, I focus on x + 10 = x^2 + x + 1 and see what can be done with it:

Subtracting x from both sides, we get 10 = x^2 + 1, which simplifies to 9 = x^2, which in turn can be solved for x:

x = plus or minus 3