Question

Multiply:
(3a-(7/9))(3a-(7/9))

Answer 1

you should memorize the pattern for squaring a binomial:
(a - b)^2 = a^2 - 2ab + b^2

so (3a - 7/9)^2
= 9a^2 - 42/9 a + 49/81
= 9a^2 - (14/3) a + 49/81