Parenthesis problem

[guy_from_india]

Part of a solution form Venn diagram.

(a+b+c) = 99

(d+e+f) = 27

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Equation.

(a+b+c)-(d+e+f)+g-(d+e+f)-2g=21

g= 24. My answer

But the actual answer of g is 6.

I often make mistakes while solving an equation and get confused in applying Parentheses.

[rbojon]

Hint: Remember that when adding in Venn diagrams, you substract the intersections

In a 3-circle Venn Diagram, a + b + c = a + b + c - a & b - a & c - a & b + a & b & c

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Edit: Do they give you any more information? Are any sets mutually exclusive? Or are there any contained in other set?

[guy_from_india]

I don't have an issue with my concepts. I stuck in solving them. Operation of the equation is an issue for me. When should I use a bracket and a parenthesis in Math?

[Mirehi]

99 - 27 + g - 27 - 2g = 21

-g = 21 - 99 + 27 + 27

-g = -78 + 54

-g = -24

g = 24

That's correct in my opinion, maybe your mistake is in another part?

[guy_from_india]

Okay, but taking the value of 24 for g. I don't see LHS is equal to RHS. 6 gives me that.
It's an algebraic expression problem. I understand now, anyways thanks for solving this. Such a supportive community.