Anonymous

# I got true for the question but the answer is false can someone please explain why its false? (A − C) − (B − C) = A − B.?

Update:

For this question I drew Venn diagrams for both sides to see if they matched and they didn't. I was told to use a membership table to see why its false. I know membership tables are like truth tables, but how do you make a membership table when there are subtraction signs in the question?

Update 2:

CORRECTION: Sorry I meant I got false for the answer and the correct answer is TRUE.

### 3 Answers

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- LônLv 73 weeks agoFavorite Answer
Remove the brackets...

A - C - B + C

= A - B

YOU are correct.... their answer is wrong.

- Anonymous3 weeks ago
Two negatives make a positive so - (-C) is +C.

Then A - C - B + C and the C's cancel out.

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Yes, you always have to remove the brackets before you simplify...thanks for BA 👍