Asked by Marysvoice
                This one showed up in the middle of my quadratic equations. There is no y or 0. What am I supposed to do with it?
Give exact and approximate solutions to three decimal places.
(x+5)^2=81
            
        Give exact and approximate solutions to three decimal places.
(x+5)^2=81
Answers
                    Answered by
            Damon
            
    x + 5 = + sqrt 81 = +9
or
x + 5 = - sqrt 81 = -9
so
x = 9-5 = 4
or
x = -9-5 = -14
check those back
    
or
x + 5 = - sqrt 81 = -9
so
x = 9-5 = 4
or
x = -9-5 = -14
check those back
                    Answered by
            Damon
            
    How to check back:
if x = 4
what is (x+5)^2 ? hint 9^2 = 81 !!!
if x = -9
what is (x+5)^2 ? hint (-9)*(-9) = 81
we did it :)
    
if x = 4
what is (x+5)^2 ? hint 9^2 = 81 !!!
if x = -9
what is (x+5)^2 ? hint (-9)*(-9) = 81
we did it :)
                    Answered by
            Damon
            
    perhaps it is coffee time
if x = -14
what is (x+5)^2 ? hint (-9)*(-9) = 81
we did it :)
    
if x = -14
what is (x+5)^2 ? hint (-9)*(-9) = 81
we did it :)
                    Answered by
            Damon
            
    Oh, and to do this as quadratic equation:
(x+5)^2 = 81
x^2 + 10 x + 25 = 81
x^2 + 10 x - 56 = 0
x = -10/2 +/- (1/2) sqrt(100 + 4*1*56)
x = -5 +/- (1/2)sqrt ( 324)
sqrt 324 = 18 by the way
x = -5 +/- 9
x = -5+9 = +4
or
x = -5-9 = -14
    
(x+5)^2 = 81
x^2 + 10 x + 25 = 81
x^2 + 10 x - 56 = 0
x = -10/2 +/- (1/2) sqrt(100 + 4*1*56)
x = -5 +/- (1/2)sqrt ( 324)
sqrt 324 = 18 by the way
x = -5 +/- 9
x = -5+9 = +4
or
x = -5-9 = -14
                    Answered by
            Damon
            
    You catching on to this ?
    
                    Answered by
            Marysvoice
            
    LOL. Your great, thanks.
    
                    Answered by
            Damon
            
    Yeah, well check the one below. I did not read carefully and left the wall of the barn out !!
    
                                                    There are no AI answers yet. The ability to request AI answers is coming soon!
                                            
                Submit Your Answer
We prioritize human answers over AI answers.
If you are human, and you can answer this question, please submit your answer.