Question 8324
when you multiply (x)(26+x) and equal that to 560 it becomes:
26(x)+(x)(x)=560 which equals 26x+{{{x^2}}}=560


{{{x^2+26x-560}}}=0
(x+40) and (x-14) comes from factoring {{{x^2+26x-560}}}=0


In order to factorize this, you must ask yourself...
what two numbers must I multiply to get 560 AND who's difference=26
If you multiply 40 and 14, you'll get 560 AND the difference of 40-14 is 26.


BUT, we can safely conclude that we will not use (x+40)=0 because then, we would be saying that someone would be a negative age.  


In this case, it would only be x-14=0 which would be used because the value of "x" would be a positive number. 


Does that make sense?