Answer:
50 cm
Explanation:
Let
x = number of months
Emma = 10 + 2x
Alice = 30 + x
Equate the equation of both girls
10 + 2x = 30 + x
10 - 30 = x - 2x
-20 = - x
x = 20
How long will their hair be?
Emma = 10 + 2x
= 10 + 2(20)
= 10 + 40
= 50cm
Alice = 30 + x
= 30 + 20
= 50 cm