Answer:
4
Explanation:
given a quadratic equation in standard form
y = ax² + bx + c = 0 : a ≠ 0
with roots α and β, then
the sum of the roots α + β = -
and
the product of the roots αβ =

2x² + 3x - 4 = 0 ← is in standard form
with a = 2, b = 3 and c = - 4
αβ =
= - 2, hence
α²β² = (αβ)² = (- 2)² = 4