Question

(x+1)+(x+2)+.....(x+41)=40x + 860

Answer 1

(x+1)+(x+2)+..........+(x+41)= 40x+860
41x + $\frac{41*42}{2}$ = 40x + 860 ( Sumele lui Gauss)
41x + 861 = 40x + 860 
41x-40x = 860 - 861
x= -1