This is a topic about power: because the values of parameters A and B are unknown, it is discussed in two cases.

1). When a+b = 0, the result approaches positive infinity;

2). When a+b is not equal to 0, it is the power, (a+b) [(-1) * (-2) * (-3) * (-4) * (-5)] = (a+b) (-128.

The above calculation process is expressed by the formula in excel, where "stands for multiplication sign and * stands for multiplication sign.