Thread: Factoring

Factor: 3x^2 - 11x + 6

Kasey

Originally Posted by flippin4u

Factor: 3x^2 - 11x + 6

Kasey

by inspection: (3x - 2)(x - 3)

by method:

Step 1:
take the first terms times the last term. we get 18x^2
take the middle term, we have -11x

Step 2:
now think of two numbers that when multiplied gives 18x^2 and when added gives -11x

the numbers are: -2x and -9x

Step 3:
rewrite the quadratic, this time writing the middle term in terms of these two numbers, we get:

3x^2 - 9x - 2x + 6

Step 4:
factor by grouping:

we have 3x common to the first two terms and -2 common to the last two, so we get:

3x(x - 3) - 2(x - 3) ........factor out the common (x - 3)

= (x - 3)(3x - 2)

By inspection?

May be this wretched Hint works

Thanks for that help. Is there anyway you could show me the steps to that. I don't know how you got that. Sorry. If you can that would be wonderful but if not, the answer was enough help. Thanks again.

Kasey

Originally Posted by flippin4u

Thanks for that help. Is there anyway you could show me the steps to that. I don't know how you got that. Sorry. If you can that would be wonderful but if not, the answer was enough help. Thanks again.

Kasey

when the coefficient of x^2 is small, like 2,3,4,5,6,7, or prime, you should be able to use inspection to figure the factors out, since there will not be many candidates for the first positions in the brackets. the method i gave you is for when you have larger numbers.