Solve for x over the real numbers:
x^3 (x^2 - 4) = 0
Split into two equations:
x^3 = 0 or x^2 - 4 = 0
Take cube roots of both sides:
x = 0 or x^2 - 4 = 0
Add 4 to both sides:
x = 0 or x^2 = 4
Take the square root of both sides:
Answer: x = 0 or x = 2 or x = -2
If both triangles are similar the ratio of sides will be same

Remember to incorporate Bimdas, into you calculation and ensure where the addition and subtraction occur you work from left to right.