Question

Please look at attached image

Answer 1

Explanation:

`{(3a - (1)/(6) b)}^(2) = 9 {a}^(2) - (1)/(2) ab - (1)/(2) ab + (1)/(36) {b}^(2)`

`= 9 {a}^(2) - ab + (1)/(36) {b}^(2)`