SOLUTION: SOLVE , GIVE EXACT AND APPRIOXMIATE SOLUTIONS TO THREE DECIMAL PLACES. Y^2 -12Y + 36=81 would like step by step so I can understand this please

Algebra ->  Radicals -> SOLUTION: SOLVE , GIVE EXACT AND APPRIOXMIATE SOLUTIONS TO THREE DECIMAL PLACES. Y^2 -12Y + 36=81 would like step by step so I can understand this please      Log On


   

Question 457450: SOLVE ,
GIVE EXACT AND APPRIOXMIATE SOLUTIONS TO THREE DECIMAL PLACES.
Y^2 -12Y + 36=81
would like step by step so I can understand this please
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

Y%5E2+-12Y+%2B+36=81
Y%5E2+-12Y+%2B+36-81=0
Y%5E2+-12Y-45=0...use quadratic formula
Y+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+

Y+=+%28-%28-12%29+%2B-+sqrt%28+%28-12%29%5E2-4%2A1%2A%28-45%29+%29%29%2F%282%2A1%29+

Y+=+%2812+%2B-+sqrt%28144%2B180+%29%29%2F2+

Y+=+%2812+%2B-+sqrt%28+324+%29%29%2F2+

Y+=+%2812+%2B-+18%29%2F2+


solutions:
Y+=+%2812+%2B18%29%2F2+
Y+=+30%2F2+
Y+=+15+
or
Y+=+%2812+-18%29%2F2+
Y+=+-6%2F2+
Y+=-3+