Respuesta :

Answer:-21

Step-by-step explanation:

X+x+1+x+2=-63

Collect like terms

X+x+x+1+2=-63

3x+3=-63

Subtract 3 from both sides

3x+3-3=-63-3

3x=-66

Divide both sides by 3

3x/3=-66/3

X=-22

The middle number x+1 is -22+1=-21