Answer:
Milan puts 1/4 of her lawn-mowing money in savings and uses 1/2 of the remaining money to pay back her sister. If she has $15 left
Step-by-step explanation:
If we call the number "x" then:
x*25%=21
x*25/100=21
x=21*4
x=84
I attached a picture with the answer, hope this helps :)
