Answer:
b² - 4ac = 0
Step-by-step explanation:
given a quadratic in standard form : ax² + bx + c : a≠ 0
the discriminant Δ = b² - 4ac
4x² - 20x + 25 is in standard form
with a = 4, b= - 20 and c = 25
b² - 4ac = (- 20)² - (4 × 4 × 25 ) = 400 - 400 = 0
