Difference between revisions of "2002 AMC 10A Problems/Problem 10"

(Solution)
 
(3 intermediate revisions by 2 users not shown)
Line 1: Line 1:
== Problem ==
+
#redirect [[2002 AMC 12A Problems/Problem 1]]
 
 
What is the sum of all of the roots of <math>(2x + 3) (x - 4) + (2x + 3) (x - 6) = 0</math>?
 
 
 
<math>\text{(A)}\ 7/2 \qquad \text{(B)}\ 4 \qquad \text{(C)}\ 5 \qquad \text{(D)}\ 7 \qquad \text{(E)}\ 13</math>
 
 
 
==Solution==
 
We expand to get <math>2x^2-8x+3x-12+2x^2-12x+3x-18=0</math> which is <math>4x^2-14x-30=0</math> after combining like terms. Using the quadratic part of Vieta's Formulas, we find the sum of the roots is <math>\boxed{\text{(A)}\ 7/2}</math>. We could also have factored, which would give a faster solution.
 

Latest revision as of 06:48, 18 February 2009