Question

Expand (x+3y+6z)² by using sutaible identity

Answer 1

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

here a = x , b = 3y , c =6z

(x+3y+6z)² = x² + (3y)² + (6z)² + 2 × x × 3y + 2 × 3y × 6z + 2 × 6z × x

(x+3y+6z)² = x² + 9y² + 36z² + 6xy + 36yz + 12zx