Look for something which you can divide both terms by. In this case both 3x and 15 are divisible by 3, so put this outside of a bracket and write the two terms divided by the common factor inside the bracket. So the answer is 3(x+5).
3(3x + 5)
3 is a factor and dividing by 3 gives x + 15 = 8x
3(x2 + 3x + 1)
3x2 + 10x + 3 = (x + 3)(3x + 1).
9x2 + 6x + 1 = 9x2 + 3x + 3x + 1 = 3x(3x + 1) + 1(3x + 1) = (3x + 1)(3x + 1) or (3x +1)2
3x^2 -14x +15 = (3x-5)(x-3)
(5x - 3)(3x + 5)
3(3x + 5)
Oh, dude, it's like this - you gotta find two numbers that multiply to -225 (15 * -15) and add up to 16. So, the numbers are 25 and -9. Then you can rewrite the equation as (5x + 25)(3x - 9). And that's how you factor it, easy peasy!
(-3x - 1)(3x - 7)
3 is a factor and dividing by 3 gives x + 15 = 8x
3(x2 + 3x + 1)
(3x + 1)(x + 5)
(x + 5)(3x + 1)
It is: 3x*(x+7)
3x(2y + 1)
(3x + 5)(3x^2 + 4)