Answer 1

In such case precedence rules will be applied. For Example 2* 5 +10

multiple has higher precedence than addition so first of all 2*5 will be solved first and then will add to ten. Below link has complete table of procesence for python

https://www.tutorialspoint.com/python/operators_precedence_example.htm

One more thing If same arithmetic operators are used then left to right rule will be applied in such cases. like

2*5*10-50 so using left to right 2*5 will solve first
10*10-50 # now multiply has higher precedence so
100-50
50