Answer:
2
Step-by-step explanation:
because 2 square is 4 then that was needed for the other squares but this one is doubled
1. a² - ( b ² - 2bc + c² ) = a ² - b ² + 2bc - c²
2. 8p² - 18 q²
3. 3ab² - c²d + 3ab - b²c²
4. x² - 2x + 1
k=0.832926