All the numbers are tilted at a 90 degree angle, except for the number 4 which it tilted at an angle of 89 degrees, hoped this helps
Answer:

Step-by-step explanation:
Let
y --->Mala's age
x---> sister's age
we know that
---> equation A
so
The sum of ages of the sisters is

substitute equation A in the expression of the sum of ages

simplify

The third and fourth charts represent functions