7. TBQ - Represent the situation in expression

Nira has a rare coin collection. She has 21 coins in one bag and 29 coins in another. She gifts her friend 9 coins from the second bag. Write an expression for the number of coins left with Nira. 

 

Expression : \(21 + (29 - 9)\)\((29 + 21) - 9\)\(21 - (29 - 9)\)\((29 - 21) - 9\)

 

Coins left \(=\)