How do you simplify #(x + 9)(x - 2)(x - 7)#?
1 Answer
Jun 12, 2017
Explanation:
#"factors of the form"#
#(x+a)(x+b)(x+c)" may be expanded as"#
#x^3+(a+b+c)x^2+(ab+bc+ac)x+abc#
#"here " a=9,b=-2" and " c=-7#
#rArr(x+9)(x-2)(x-7)#
#=x^3+(9-2-7)x^2+(-18+14-63)x+(9xx-2xx-7)#
#=x^3-67x+126#
