The first thing that you should notice is that the coefficient of the leading term is greater than 1, in this case, it's 3.
You will need to factor by grouping, to do this use to following steps.
Step 1: If a > 1, multiply 'a' times 'c'.
Step 2:Find two numbers whose sum is equal to 'b' and whose product is equal to 'ac'.
Step 3: Rewrite your equation as where and are the numbers that you found in Step 2. Tip: Look at the numbers that you've found and group them wisely, this will aid in factoring. You'll see what I mean below.
Step 4: Factor both groups independently. This will leave you with two terms with a binomial factor in common.
Step 5: Factor out the binomial.
The original quadratic.
Two numbers that add to be -7 and multiply to be -18 are -9 and 2.
Rewrite using our two numbers. Notice how 3 is a factor of 9 and 2 is a factor of 6? We could have written it the other way but it would have been more work to factor.
Factor the two groups independently. See how both terms now have the common factor