Answer:
Let karly's age be x
mona is four years older
mona = 4+x
Alexis it twice as old as mona
alexis= 2(4+x)
alexis= 8+2x
the sum of their ages is 48
x + 4+x + 8+2x= 48
4x+12=48
4x=48-12
4x=36
x=9
katly is nine years old
mona = 4+x
mona = 4+9
mona = 13
mona is 13 years old
alexis = 8+ 2x
alexis = 8+ 2(9)
alexis = 8+18
alexis = 26
alexis is 26 years old
