FOILing (a - b)(a + b)
    F Take the product of the First terms a.a = a2
    O Take the product of the Outer terms a.b = ab
    I Take the product of the Inner terms (-b).a = -ab
    L Take the product of the Last terms (-b).b = -b2
    Then add them all up a2 + ab - ab - b2  =   a2 - b2

Enter this as   a^2 - b^2

 


Just close this window to return to the tutorial.
Lost the tutorial to which this window is attached? Press here.