SOLUTION: Hi. I have a question for you. I am working on a problem and here it is: 4x^2-44x+72=0 The least common multiple would be 4 so if I divide each term by 4, I end up with 4(x^2-1

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Hi. I have a question for you. I am working on a problem and here it is: 4x^2-44x+72=0 The least common multiple would be 4 so if I divide each term by 4, I end up with 4(x^2-1      Log On


   

Question 987360: Hi. I have a question for you. I am working on a problem and here it is:
4x^2-44x+72=0
The least common multiple would be 4 so if I divide each term by 4, I end up with 4(x^2-11x+18=0) My confusion is this. I checked the answer and the answer is (x=2)(x=9) what happened to the four? Can you shed some light on this?

Found 2 solutions by ikleyn, MathTherapy:
Answer by ikleyn(52786) About Me  (Show Source):
You can put this solution on YOUR website!
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Your equation is

4x%5E2 - 44x + 72 = 0.

Divide both sides by  4.  You will get

x%5E2 - 11x + 18 = 0.

The roots are  2  and  9  (you can use the quadratic formula or the Vieta;s theorem).



Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!
Hi. I have a question for you. I am working on a problem and here it is:
4x^2-44x+72=0
The least common multiple would be 4 so if I divide each term by 4, I end up with 4(x^2-11x+18=0) My confusion is this. I checked the answer and the answer is (x=2)(x=9) what happened to the four? Can you shed some light on this?
FYI: 4 is the GCF (greatest common factor) of the equation, NOT the LCM

When you divided by 4, you were supposed to get: 4%28x%5E2+-+11x+%2B+18%29+=+4%280%29

Do you see how this was done? You should've divided BOTH sides by 4, not just the left side

Now, 4 = 4, and what's in the parentheses are set equal to each other

So, we have: 4 = 4 (TRUE), and highlight_green%28x%5E2+-+11x+%2B+18+=+0%29. The  quadratic equation is then factored and solved for x to get roots of 2 and 9.