The area of a rectangle is x2 + 4x -12. What are the dimensions of the rectangle (length and width)?  Choose the correct choice from the following answers:
A) x + 6 , x + -2  B) x + 7 , x + -2  C) x + 8 , x + -2  D) x + 9 , x + -2  E) none
Solution   The main idea is to factor x2 + 4x -12   Since -12 = -2 × 6 and   -2 + 6= 
<gadget id="calculator">  -2 + 6</gadget>
<output>4</output>
4   x2 + 4x -12= ( x + -2) × ( x + 6)   Since the length is usually longer, lenth = x + 6 and width = x + -2   x + 6 , x + -2nswer x + 6 , x + -2
<result>A</result>
The area of a rectangle is x2 + 4x -12. What are the dimensions of the rectangle (length and width)?