SOLUTION: factor the quadratic expression completely, and find the roots of the expression. 6x^2 - 42x + 72

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: factor the quadratic expression completely, and find the roots of the expression. 6x^2 - 42x + 72      Log On


   

Question 36336: factor the quadratic expression completely, and find the roots of the expression.
6x^2 - 42x + 72
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Factor the expression:
6x%5E2-42x%2B72 First factor out a 6.
6%28x%5E2-7%2B12%29 Now factor the parentheses.
6%28x-3%29%28x-4%29
To find the roots, you must have an "equation". So presumably, you mean this expression to be equal to zero.
6x%5E2-42x%2B72+=+0 Now we can find the roots. Factor as above.
6%28x-3%29%28x-4%29+=+0 Apply the zero products principle. 6 is not zero, so:
%28x-3%29%28x-4%29+=+0 Apply the zero products principle again.
x-3+=+0 and/or x-4+=+0
If x-3+=+0 then x+=+3
If x-4+=+0 then x+=+4
The roots are:
x = 3
x = 4