Answer
See explanation
Work Step by Step
(a) Operator precedence is the priority order of operators i.e. the order in which the operators are calculated. An operator with higher precedence is calculated first. For example in equation $a+b*c$ the operator * have higher precedence, so b*c will be calculated first and then a will be added to the result.
(b) $2\times3$ will be calculated first because multiplication have higher precedence than addition, after multiplication we will get 6 which will be added to 6 and the final result will be 12.
