SOLUTION: Give an exact and approximate solutions to three decimal points. y^2 - 18y + 81 = 64 Type an exact number, use radicals if necessary, rationalize all denominators, express

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Give an exact and approximate solutions to three decimal points. y^2 - 18y + 81 = 64 Type an exact number, use radicals if necessary, rationalize all denominators, express       Log On


   

Question 321266: Give an exact and approximate solutions to three decimal points.
y^2 - 18y + 81 = 64
Type an exact number, use radicals if necessary, rationalize all denominators, express complex terms in terms of i, and use comma to separate.
Thank you!!
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
y%5E2+-+18y+%2B+81+=+64 Start with the given equation.


%28y-9%29%5E2=64 Factor the left side.


x-9=%22%22%2B-sqrt%2864%29 Take the square root of both sides.


y-9=sqrt%2864%29 or y-9=-sqrt%2864%29 Break up the "plus/minus" to form two equations.


y-9=8 or y-9=-8 Take the square root of 64 to get 8.


y=9%2B8 or y=9-8 Add 9 to both sides.


y=17 or y=1 Combine like terms.


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Answer:


So the solutions are y=17 or y=1.