The area of a rectangle is represented by the polynomial x^2 + 3x - 6x - 18. Find the possible expressions for the length and width of the rectangle.

Question

welshfella · Answer

x^2 + 3x - 6x - 18
= x^2 - 3x - 18

you now need to factor the above

welshfella · Answer

oh - silly me its easier to factor in its original form
you can factor that by grouping the first 2 and last 2 terms

amberlykhan · Answer

How do you find the length and width expressions after that?

welshfella · Answer

x^2 + 3x - 6x - 18
= x(x + 3) - 6x - 18

can you find the factors of the last 2 terms?

amberlykhan · Answer

6.

amberlykhan · Answer

So it would be -6(x - 3).

welshfella · Answer

Hint;-   its -6 and another expression in paremteses

amberlykhan · Answer

+3

welshfella · Answer

right
-6(x+ 3)

now we have 
x(x +3) - 6(x + 3)

can you continue?

amberlykhan · Answer

I don't know what to do.

welshfella · Answer

you can simplify this further
Note that (x +3) is common to the 2 'halves' of the expression

welshfella · Answer

sorry but i have to go right now

amberlykhan · Answer

Oh, I got it. It would be written as (x - 6)(x + 3), which represents the length x the width. Thanks!