Mathematics for IGCSE & O level - Algebraic Manipulation (Section 5 - No. 22)
What do you have to do to the expression 2x² - 8 before attempting to factor it?
Complete the square
Factor out the GCF (2)
Apply the quadratic formula
Group the terms
Explication
The GCF is 2, so factor it out first to get 2(x² - 4)