Can #y= x^2-3x-28 # be factored? If so what are the factors ?
1 Answer
Explanation:
Luckily, your
I would like to suggest the following method:
If your factorization exists, it would look like this:
So, your goal is to find
#a + b = -3# #color(white)(i)a xx b color(white)(i) = -28#
It is always easier to start with the multiplication. Since
Possible integer pairs of
#(-4) xx 7 color(white)(xx)# or#color(white)(xx) 4 xx (-7)# #(-2) xx 14 color(white)(xii)# or#color(white)(xx)2 xx (-14)# #(-1) xx 28 color(white)(xii)# or#color(white)(xx)1 xx (-28)#
It is easy to check that the correct pair is
Thus, your factorization is
#color(white)(x)#
By the way, this also means that the solutions for the equation
are