Respuesta :

Step 1: move 64 to a left side, -13 - 64 = 7d

Step 2: -77 = 7d

Step 3: [tex] \frac{-77}{7} [/tex] = d

Step 4: d = -11
it is d=11
because u subtract the negative 64 with a positive for a positive and negative turn 0 then u got to do the same side with -13-(-64)=7d then u add -13+-64=77 after u done that it will be 77=7d divide it by 7 on both side then u get d=11