Is it possible to factor #y=x^2 +8x+15#? If so, what are the factors?

1 Answer
Dec 24, 2015

Answer:

#y=x^2+8x+15= color(green)((x+3)(x+5))#

Explanation:

Since #(x+a)(x+b) = x^2+(a+b)x+ab#

we need to find two numbers #a# and #b#
such that
#color(white)("XXX")a+b=8#
and
#color(white)("XXX")ab=15#

Checking factors of #15# we quickly come up with #3# and #5# which sum to #8#