Question

(z-2/3) (z+2/3)
identities
use direct methodo to evaluate
step by step​

Answer 1

To evaluate :  $\sf{ \left( z - {\dfrac{2}{3}} \right) \left( z + {\dfrac{2}{3}} \right) }$

• Identity - (a - b)(a + b) = a² - b²

             Here, a = z, b = 2/3

⇒ $\sf{ (z)^2 - \left( {\dfrac{2}{3}} \right) ^2 }$

⇒ ${\boxed{\sf{ z^2 - {\dfrac{4}{9}} }}}$

Answer 2

Answer:

answer- Z[Z+⅔]-⅔[Z⅔]

=Z²+⅔-⅔+4/9

=Z²-4/9