VBODMAS

  • V : Virnaculum or bar
  • B : Bracket
  • O : Of
  • D : Division
  • M : Multiplication
  • A : Addition
  • S : Subtraction

Modulus

Modulus of a real number x is its positive value, denoted by |x|.
Thus, |7| = 7 and |−7| = 7

Formulas :

(a + b)2 = a2 + b2 + 2ab

(a − b)2 = a2 + b2 − 2ab

(a + b)(a − b) = a2 − b2

(a + b)2 − (a − b)2 = 4ab

(a + b)2 + (a − b)2 = 2 (a2 + b2)

(a + b + c)2 = a2 + b2 + c2 + 2 (ab + bc + ac)

(a3 + b3) = (a + b) (a2 − ab + b2)

(a3 − b3) = (a − b) (a2 + ab + b2)

(a + b)3 = a3 + b3 + 3ab(a + b)

(a − b)3 = a3 − b3 − 3ab(a − b)

(a3 + b3 + c3 − 3abc) = (a + b + c) (a2 + b2 + c2 − (ab + bc + ca))

If a + b + c = 0, then a3 + b3 + c3 = 3abc