✔ 最佳答案
6x² + 4x - 2 I like to factor this by grouping. To do so, we want to expand the middle term + 4x. Take the 6 from the x^2 term and multiply it by the -2 at the end. This gives you -12. Now, can we find two factors of -12 with a sum of +4 ? Yes, with +6 and -2, we get -12 as a product and +4 as a sum. So expand the +4x using these numbers.
6x² + 6x - 2x - 2
Now group them two at a time:
(6x² + 6x) + (- 2x - 2)
Now factor what is common from each:
6x(x + 1) -2(x + 1)
Now factor the common factor: (x + 1)(6x - 2)
Your answer is: ( x + 1 )( 6x - 2 )
For your second problem, you must recognize it as a difference of two squares. Use the formula: A² - B² =( A - B)(A + B)
In the case of x² - 36, your A = x and your B = 6
So, x² - 6² = (x - 6)(x + 6)
This third one doesn't fall into the category of difference of cubes, but in general, if you have something of the form A³ - B³ this is known as the difference of cubes and factors as follows:
A³ - B³= (A - B)(A² + AB + B²)
Hope this helped
Edit. In problem 2, the final answer is not correct. I failed to factor out a 2. So, your answer should be:
2( x + 1 )( 3x - 1 )
Also, 3) doesn't factor using rational numbers. It will factor if you use radical expressions(square roots). Note also that the person above who did factor it did so incorrectly.