Task
Select a numeric expression equal to the expression:
\(\displaystyle 305+(34+79)=\)
Solution
In this problem we use the associative law of addition:
The sum does not depend on the grouping of the terms:
\(\displaystyle a+(b+с)=(a+b)+c{\small .}\)
Therefore,
\(\displaystyle 305+(34+79)=(305+34)+79{\small . }\)
Moreover,
\(\displaystyle (305+34)+79=418=305+(34+79){\small , }\)
\(\displaystyle (305-34)+79=350 =\not 418=305+(34+79){\small , }\)
\(\displaystyle (503+34)+79=616 =\not 418=305+(34+79){\small , }\)
\(\displaystyle 305-(34+79)=192 =\not 418=305+(34+79){\small . }\)
Answer: \(\displaystyle (305+34)+79{\small . }\)