=G31*1.5+3 or =(G31*1.5)+3
=4+9
It has no special name. It is just the plus sign.
83 + 2 = 85 (Excel formula: =83+2)
This question is irrelative because C++ is a language and Excel is a software. The thing is that we can't use C++ with Excel, but we can write a program like excel in C++.
For =A1+B1, the operator is the plus sign (+).
85
The combined sign has no special meaning. Any formula in Excel starts with an equal sign. To refer to a cell, you can write, for example, =A1. This can also be written as =+A1. The "+" isn't really necessary in this case. Most likely, a user started the formula with a "+" (out of old habit, since that's what people used to do in older spreadsheet programs), and Excel added the equal sign, which is required in Excel, automatically.
48
26
26
The plus sign is an operator, not an operand. An operand is something that an operator operates on. For example, A3 and 10 are the operands in the following formula and the operator is the plus sign. =A3+10
You need a formula. That formula can use the Sum function or it could use the plus sign, or several plus signs and even several Sum functions. Primarily it is the Sum function and the plus sign that is used for sums.