Question

Perfect square trinomial:

(a – b)2 = (a – b)(a – b) = a2 – 2ab + b2
Find the product of (k – 9)2 using the perfect square trinomial rule shown on the left.



The product (k – 9)2 can also be written as
.

The product is k2 –
k +
.

Answer 1

See work below.

Explanation:

`(k-9)^2=(k-9)(k-9)\\=k^2-2(k)(9)+9^2\\=k^2-18k+81`