Need help with a quick math problem?: (b - 2/3)^2 + 4/9 = 0

Again the problem is (b - 2/3)^2 or to the second power + 4/9 = 0

and if you can explain to me how to do this problem thank you very much :)

Okay, first you need to distribute the ^2 into the parenthesis.
b^2-(2^2/3^2)+(4/9)=0
Then figure out what the value is in the parenthesis.
b^2-(4/9)+(4/9)=0
The 4/9 end up cancelling each other.
b^2=0
Take the square root of both sides.
b=0
Hope this helps!