Re-write the quadratic function below in Standard Form
y= –2(x + 5)(x – 4)

y = - 2x² - 2x + 40

Step-by-step explanation:

Standard form of a quadratic is y = ax² + bx + c : a ≠ 0

Given

y = - 2(x + 5)(x - 4) ← expand factors using FOIL

  = - 2(x² - 4x + 5x - 20)

  = - 2(x² + x - 20) ← distribute parenthesis by - 2

  = - 2x² - 2x + 40 ← in standard form

step-by-step explanation: a reaction is first order. if the initial reactant concentration is 0.0200 m, and 25.0 days later the concentration is 6.25 x 10-4 m, then its half-life is: