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Algebra - Quadratic Equation











































solve 5x^2=-35x answer should include the complete solution set

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Jul 15, 2011
Algebra - Quadratic Equation
by: Staff


The question:

solve 5x^2=-35x answer should include the complete solution set


The answer:

5x^2=-35x

5x^2 + 35x =-35x + 35x

5x^2 + 35x = 0


Factor the left side of the equation

x*(5x + 35) = 0


The two solutions for x are:


Solution #1


x*(5x + 35) = 0

divide each side of the equation by (5x + 35)

x*[(5x + 35)/(5x + 35)] = 0/(5x + 35)

x*[(5x + 35)/(5x + 35)] = 0

x*(1) = 0

x = 0


Solution #2


x*(5x + 35) = 0

divide each side of the equation by x

(5x + 35)*(x/x) = 0/x

(5x + 35)*(x/x) = 0

(5x + 35)*(1) = 0

(5x + 35) = 0

5x + 35 = 0

Subtract 35 from each side of the equation

5x + 35 - 35 = 0 - 35

5x + 0 = 0 - 35

5x = 0 - 35

5x = -35


Divide each side of the equation by 5

5x/5 = -35/5

x*(5/5) = -35/5

x*(1) = -35/5

x = -35/5

x = -7


The final answer is: x = {0,-7}



Check the work by substituting the values of x into the original equation:

For x = 0

5x^2=-35x

5*(0)^2=-35*0

5*(0)=-35*0

0 = 0, OK


For x = -7

5x^2=-35x

5*(-7)^2=-35*(-7)

5*49=-35*(-7)

245 = 245, OK




Thanks for writing.

Staff
www.solving-math-problems.com



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