give exact and approximate solutions to 3 decimal points y^2-18y 81=49

I suspect that a '+' sign didn't come through in the subject of your post - it should read


y^2 -18y+81=49


Correct?

You can factor the left hand side - it turns out to be a square. Note that the right hand side is also a square - so take square root of both sides and it's pretty easy from there to get one of the solutions.

Or you can subtract 49 from both sides and factor, which will give you both solutions.

(-2x2)3(-5xy6)2