How do you factor the trinomial #r^2 + 6r + 5#?

1 Answer
Jan 20, 2016

#(r+1) (r+5)#

Explanation:

This is a quadratic equation. The square root of #r^2# is r. However, the square root of 5 is not a whole number. So, to factor this we have to consider the FOIL method; First term, outer term, inner term and last term.

Remember that, #(ax+b)(ax+c) = ((ax)^2 + bax + cax + bc)#

#(r^2+ 6r +5) = (r+1) (r+5)#
#(r^2+ 6r +5) = (r^2 + 1r +5r +5)#
#(r^2+ 6r +5) = (r^2 + 6r +5)#