Algebra

I was given this answers to a problems I solved but I do not understand what she means hope you can help.

Before attempting to solve this quadratic equation, determine how many solutions there will be for this quadratic equation. Explain your reasoning. Finally, solve the equation.
(x - 9)2 = 81

I too, came up with the same answer and agree that this is a positive number and we should expect there to be two solutions to this problem. Carrying out the square is exactly the same as using the quadratic formula it is where you substitute a, b and c into the formula. It gives you the same answer to the polynomial used. This is because the quadratic formula came from finishing the square. Completing the square method is like the father of the quadratic formula.

(x - 9)2 = 81
(x - 9) = �ã81
x = 9�}9
x = 18 or x = 0

This answer was inreponce to another student who came up with the same as i did.

Hi Charly,

Yes, your answer is correct. Nice work. However, the method you used is not completing the square. Which one might it be, do you think?

  1. 👍 0
  2. 👎 0
  3. 👁 484
  1. For you information, online "^" indicates an exponent, e.g., x^2 = x squared.

    (x - 9)^2 = 81

    x^2 -18x + 81 = 81

    x^2 - 18x = 0

    x(x-18) = 0

    X = 18 or 0

    1. 👍 0
    2. 👎 0
  2. Monash University - one of the top universities in Australia

Respond to this Question

First Name

Your Response

Similar Questions

  1. Math-PLEASE check my answers

    What types of problems can be solved using the greatest common factor? What types of problems can be solved using the least common multiple? Complete the explanation. *** Use the words 'same' and 'different' to complete the

    asked by Sam on September 11, 2014
  2. Math - Ms. Sue

    1) Which is M = 9pn solved for p? a. p = M/n b. p = M - 9n c. p = 9n/M d. p = M/9n 2) Which is M = 300J/P solved for J? a. J = 300PM b. J = 300M/P c. J = 3OO/PM d. J = PM/300 I don't really understand this but my answer are 1. d

    asked by Nalea on April 10, 2015
  3. Algebra problems

    I have some problems that I would like checked please. Find and simplify the difference quotient f(x+h)-f(x)/h, h can not equal 0 for the given functions. 1. f(x)=x^2+3x+9- I got 2x+h+3 Evaluate the piecewise function at the given

    asked by Soly on September 5, 2007
  4. To Troyer 0269

    I deleted your last science post, as I promised I would a couple of weeks ago. You posted five questions that I'm sure you could answer by reading your text. As you know, we don't give answers, but help students with problems they

    asked by Ms. Sue on December 14, 2008
  1. biology

    On a television talk show, a guest claims that people who exercise vigorously for 15 minutes or more every day are able to solve math problems more rapidly than people who have no vigorous exercise in their daily routine. Describe

    asked by ms.sue help on December 23, 2013
  2. Comunications

    Prescribe solutions for business communication problems. This sounds like the subject of a major paper. In general, most communication problems are solved by telling the truth, being very clear about your objectives, and

    asked by Dan on January 3, 2007
  3. math

    I need the answers to why did the banana go out with the prune. I already know the answer to the riddle i just need to know the answers to all the problems. Teachers i am a cheater, deal with it there are cheaters and i am one of

    asked by Hugh Mungus on November 28, 2016
  4. geometry

    m

    asked by lilman on May 14, 2012
  1. CALCULUS

    Could someone please solve these four problems with explanations? I'd like to understand how to get to the answers. Thank you! Without using a calculator: For each of the following, find: I. lim x->a- f(x) II. lim x->a+ f(x) III.

    asked by Samantha on November 10, 2013
  2. biostats

    Suppose we divide the patients according to whether or not they received antibiotics, and calculate the mean and standard deviation for each of the two subsamples: answers: x, s, n x sd n Antibiotics 11.57, 8.81, 7 No antibiotics

    asked by maria on July 21, 2017
  3. Law and Ethics

    Hi, I'm a incoming freshmen to a university. Over the summer I obtained the book that we would be using for a course. I have spent several hundred hours of self research and self teaching reading the whole entire book and solving

    asked by George on July 12, 2011
  4. Math

    CAN SOMEONE CHECK MY ANSWERS PLEASE? What types of problems can be solved using the greatest common factor? What types of problems can be solved using the least common multiple? Complete the explanation. *** Use the words 'same'

    asked by Sam on September 11, 2014

You can view more similar questions or ask a new question.