Question

a) Find the product using suitable identity
(9a-7b) (9 a +7b)
b) show that: (9x-5y)²
+ 180xy = (9x + 5y)²​

Answer 1

Answer:

Solution,

(9a-7b) (9a+7b)

(9a)²-(7b)². [(a+b)(a-b)=a²-b²]

=81a²-49b²