# Algebra - Square Root Problem

by danny
(union)

36x² - 81

Solve the following quadratic equation for the two values of x.

Do not use the quadratic formula.

### Comments for Algebra - Square Root Problem

 Mar 23, 2011 Algebra - Square Root Problem by: Staff The question: by Danny (Union)36x^2-81The answer:Although your submission does not have an equal sign, I presume you need to solve for x in the following equation:36x² - 81 = 0To solve this equation, begin by adding 81 to each side of the equation.36x² - 81 + 81 = 0 + 8136x² - 81 + 81 = 8136x² + 0 = 8136x² = 81The next step is to take the square root of each side of the equation.sqrt(36x²) = sqrt(81)6x = 9Divide each side of the equation by 6.6x/6 = 9/6x * (6/6) = 9/6x * (1) = 9/6x = 9/6Reduce the fraction 9/6 to the lowest terms.x = 9/6x = (3*3)/(2*3)x = (3/2)*(3/3)x = (3/2)*(1)x = 3/2 (or 1.5, if you prefer)the final answer is: x = ±3/2the last step: check the work. Substitute 3/2 for x in the original equation.36x² - 81 = 036*x² - 81 = 036*(3/2)² - 81 = 036*(3/2)*(3/2) - 81 = 0(36*3*3)/(2*2) - 81 = 0(324/4) - 81 = 081 - 81 = 00 = 0Since 0 does = 0, the solution for x is correct. x = 3/2.Final note:As you know, x^2 and x² stand for the same thing.If you prefer, you can type x² using your keyboard as follows:Type "x", then hold down the Alt key on your keyboard. While the Alt key is depressed, type 0178. Then release the alt key. The result will be:x²Thanks for writing.Staff www.solving-math-problems.com

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