Question

class 9 math ch 1 all formula​

Answer 1

Answer:

Important Formulas of Number System

( a + b)(a - b) = (a2 - b2)

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

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

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

( a3 + b3) = (a + b)(a2 - ab + b2)

( a3 - b3) = (a - b)(a2 + ab + b2)