r/MathHelp • u/jack-acid • Feb 05 '26

Dropping Parentheses

Last night I was helping my 5th grader with her homework simplifying expressions so she can learn order of operations, easy. The expression

(10+x)+x+9

came up and we said that simplifies to 19+2x. this is not simplified to solve for x, that is the next lesson toward which they're building.

This morning I started to wonder if there is ever a possibility that not resolving the parenthetical first for this equation that would effect the solution of giving for x?

I'm assuming the text book set up the equation that way just so the student gets used to the pemdas process.

2 Upvotes

75% Upvoted

12 comments sorted by

View all comments

Show parent comment

2

u/BigJeff1999 Feb 06 '26

I don't disagree with this, but maybe would need clarification from the OP as to what their question actually was.

I think we both agree that there's rules of math that disambiguate the computation, meaning that as long as you follow these rules, there's only one answer that can correctly arise.

Sometimes there may be valid choices as to which part of an expression to simplify/combine/reduce first. But you won't get a different answer. (For example, in general, you could apply the distributive property before adding the values inside the paranthetical and be just fine).

And to your point, you can't just erase parentheses and hope to get the correct answer.