Question

Simplify using suitable identity : (7b-9c)(7b-9c)​

Answer 1

Answer:

49b²-126bc+81c²

Step-by-step explanation:

we know that (x-y)² = x²-2xy+y²

so, (7b-9c)(7b-9c) = (7b-9c)²

=> (7b)²-2(7b)(9c)+(9c)²

=> 49b²-126bc+81c²

Answered by Gauthmath