Answer:
Meaning of Aisha's first expression : 2·(10 - k)
2 : It shows that the Eli's money is doubled
10 : It the initial amount of money that Eli has at the starting
k : It shows the amount of money that is lost
10 - k : It is the amount of money which is left with Eli after losing some amount of money.
Meaning of Aisha's second expression : 20·k - 2·k
20 : It is the twice of initial amount of money which Eli has
k : It shows the amount of money that is lost
2k : It shows the twice of amount of money that is lost
20 - 2k : It is the amount of money which is left with Eli after his mom has given him some amount of money