I don't know a very easy method...
The first factor plus added to the second factor is always the term in the middle (-5 + -12 = -17); the first factor multiplied with the second factor is always the last term in the basic equation (-12 * -5 = 60).

Note that the two numbers were are looking for sum - 17 and yield a product of 60, which means that both are negative. As the product is 60, one of the numbers is going to be a multiple of 5

Here is one of the method to factor it

•Make sure that the coefficient on the term is equal to 1. rewrite it so that the X^2 and x terms are on one side and the constant is on the other side. X^2 -10X + 9= 0 as X^2 –10X = -9
•Then take out (b/2)2 for e.g (-10/2)2 = 25
•Add that to both sides of eqn X^2 –10X + 25 = -9 + 25
•X^2 –10X +25 = 16
•(X – 5)^2 = 4^2
•X – 5 = 4, X = -9
•And X-5 = -4, X=1

veekay wrote:Here is one of the method to factor it

•Make sure that the coefficient on the term is equal to 1. rewrite it so that the X^2 and x terms are on one side and the constant is on the other side. X^2 -10X + 9= 0 as X^2 –10X = -9
•Then take out (b/2)2 for e.g (-10/2)2 = 25
•Add that to both sides of eqn X^2 –10X + 25 = -9 + 25
•X^2 –10X +25 = 16
•(X – 5)^2 = 4^2
•X – 5 = 4, X = -9
•And X-5 = -4, X=1

Nice! You might as well use the quadratic formula.
I recommend learning to factor by inspection, as it will improve your computational skills

kevincanspain wrote:Nice! You might as well use the quadratic formula.

what formula do you mean?

erdnah wrote:

kevincanspain wrote:Nice! You might as well use the quadratic formula.

what formula do you mean?

[-b+/-sqrt(b^2-4ac)]/2a