You have defined x to be the smaller of two consecutive integers. Then the larger will be (x+1). The given relation is
... (x) + 3(x+1) = -5 . . . . the smaller plus 3 times the larger is -5
... 4x + 3 = -5 . . . . . . . .simplify
... 4x = -8 . . . . . . . . . . subtract 3
... x = -2 . . . . . . . . . . . divide by the coefficient of x
The smaller of the two integers is -2.
