How do you use synthetic division to divide 4a^2 + 19a + 214a2+19a+21 by a+1a+1?

1 Answer
Oct 14, 2015

4a^2 + 19a + 214a2+19a+21 divided by a+1a+1

a+1=a-(-1)a+1=a(1)

"-1" ||-1 "4 " " " "19 " " " "21 "4 19 21
++ "" " " " " "" "-4" " " " -15" " -4 -15
"" " " ------
" "" "4" "15" "|6" " 4 15 6

The quotient is 4a+154a+15 and the remainder is 66

We can check our answer by finding:

(a+1)(4a+15) + 6(a+1)(4a+15)+6

= 4a^2+15a+4a+15 + 6=4a2+15a+4a+15+6

= 4a^2+19a+21=4a2+19a+21 which is the dividend.