Respuesta :

All numbers in each number add up to 9, i dont know if you understand me, 
for example:
1+8=9
2+2+5=9
2+7=9
.....

MissPhiladelphia
In mathematics, an arithmetic progression (AP) or arithmetic sequence is a sequence of numbers such that the difference between the consecutive terms is constant. The common difference would be calculated as follows:


–36 - –31.5  = - 4.5 
–27 - –22.5  = -4.5

Therefore, the common difference is -4.5.