Respuesta :

we shall take X as the total amount of cash her piggy bank can hold
therefore 1x/10+400=1x/2
400=1x/2-1x/10
we should make the denominator's the same
400=5x/10-1x/10
400=4x/10
400*10=4x
4000=4x
4000/4=X
1000=X
hope u found this useful