Question

81a²-72ab+16b² factorise​

Answer 1

Step-by-step explanation:

${81a}^{2} - 72ab + {16b}^{2} \\ = {(9a)}^{2} - (2)(9a)(4b) + {4b}^{2} \\ this \: is \: in \: the \: fomat \: of \: {(a + b)}^{2} \\ so \\ = {(9a - 4b)}^{2} \\ = (9a - 4b)(9a - 4b)$

Answer 2

Answer:

81a²-72ab+16b²= (9a-4b)²

Step-by-step explanation:

81a²-72ab+16b²

=( 9a)² -2(9a)(4b)+(4b)²

=(9a-4b)(9a-4b)

=(9a-4b)²