Answer:
[tex]2(y+2)[/tex]
Step-by-step explanation:
Let
y --->Mala's age
x---> sister's age
we know that
[tex]x=y+4[/tex] ---> equation A
so
The sum of ages of the sisters is
[tex]x+y[/tex]
substitute equation A in the expression of the sum of ages
[tex](y+4)+y=2y+4[/tex]
simplify
[tex]2(y+2)[/tex]