Answer: 55cm + X*4cm < Y.
Explanation:
The initial height of the tree is 55cm
The tree will grow 4cm per month, for X months.
then the height of the tree is the initial height, plus X times 4cm
H = 55cm + X*4cm
If Y is the maximum height that this tree can grow, then we can write the inequality as:
H < Y.
55cm + X*4cm < Y.