Question

What is the factored form of the binomial expansion 81x^2 + 144xy + 64y^2?

(9x – 8y)^2
(9x + 8y)^2
(3x – 4y)^2
(3x + 4y)^2

Answer 1

option b)

Explanation:

a² + 2ab + b² = (a + b)²

81x² = 9*9*x² = (9x)²

64y² = 8*8*y² = (8y)²

81x² + 144xy + 64y² = (9x)² + 2* 9x * 8y + (8y)²

= (9x + 8y)²

Answer 2

( 9x+8y)^2

Explanation:

81x^2 + 144xy + 64y^2

We recognize that this is a perfect square trinomial

perfect square trinomial is of the form: and factors to

(ax)2 + 2abx + b2 = (ax + b)2

(9x)^2 + 2 * 9x * 8y + (8y)*2 = ( 9x+8y)^2