Mathematics for IGCSE & O level - Algebraic Manipulation (Section 7 - No. 17)
What is the result of expanding (x - 4)(x + 2)?
x^2 - 2x - 8
x^2 + 2x - 8
x^2 - 6x + 8
x^2 + 6x + 8
คำอธิบาย
Using the FOIL method: (x - 4)(x + 2) = x^2 + 2x - 4x - 8 = x^2 - 2x - 8