
Edward A. answered 02/07/20
Math Tutor, Retired Computer Scientist and Technical Communicator
Hi David, it’s because we have a specific order in which we perform the three operations ( +, x, -), and its not left-to-right.
Teachers use the “word” PEMDAS, to remember the order.
P arentheses
E xponentiation
M ultiplication
D ivision
A ddition
S ubtraction
in your problem, we have Multiplication first, so:
4 + 5x5 -2
4 + 25 -2
Then Addition
29 - 2
Then Subtraction
27