I have another question

Question

Y² - 2/3 + 1/9 = 0

Answer 1

Again we have a perfect square.

 

Same process:  y² - 2/3y + 1/9 = 0     (How do we know that this is a perfect square?   Take 1/2 of 2/3 = 1/3,  square  that and we get 1/9)

 

y² - 2/3y + 1/9 = 0

 

(y - 1/3)² = 0

 

|y - 1/3| = 0

 

So y = 1/3,    Since this is a perfect square, we have 2 roots, both are equal to 1/3 multiplicity of 2.