That is called "factoring".
16n
4m
It is: 15x
product
There is no special name - other than product.
16n
2g
10n
It is: 15x
3x
13c
13c
4m
128
The result after multiplying a set of numbers or algebraic expressions is called the product. In mathematics, when two or more factors are multiplied together, the outcome is referred to as the product of those factors. For example, in the expression (3 \times 4), the product is 12. Similarly, for algebraic expressions, such as (x \cdot y), the product is represented as (xy).
2b=c
7E