Why we should use only distributive law to prove that (a + b)2 = a2 + 2ab + b2 ?
Answer :
We can write ( a + b )2 , As :
( a + b ) ( a + b ) , So to solve this we use distributive law , As here we want to find multiplication of these two terms and in associative and commutative properties we just rearrange these terms , So we get by using distributive law
( a + b ) ( a + b ) = a2 + ab + ab + b2
( a + b )2 = a2 + 2 ab + b2
We can write ( a + b )2 , As :
( a + b ) ( a + b ) , So to solve this we use distributive law , As here we want to find multiplication of these two terms and in associative and commutative properties we just rearrange these terms , So we get by using distributive law
( a + b ) ( a + b ) = a2 + ab + ab + b2
( a + b )2 = a2 + 2 ab + b2