Answer:
see explanation
Step-by-step explanation:
This is a quadratic equation
Rearrange into standard form : ax² + bx + c = 0 : a ≠ 0
subtract 20e from both sides
25e² - 20e + 4 = 0 ← in standard form
This is a perfect square of the form
(a - b)² = a² - 2ab + b²
25e² = (5e)² ⇒ a = 5e and 4 = 2² ⇒ b = 2, and
- 2ab = - 2 × 5e × 2 = - 20e, hence
25e² - 20e + 4 = (5e - 2)²
⇒ (5e - 2)² = 0 ⇒ e = with multiplicity 2