Come si semplifica # (x-3) ^ 3 #?
Risposta:
#x^3-9x^2+27x-27#
Spiegazione:
#"Given " (x+a)(x+b)(x+c)" then expansion is"#
#x^3+(a+b+c)x^2+(ab+bc+ac)x+abc#
#rArr(x-3)^3#
#=(x-3)(x-3)(x-3)#
#"with " a=b=c=-3#
#rArr(x-3)^3#
#=x^3+(-3-3-3)x^2+(9+9+9)x#
#color(white)(xx)+(-3)(-3)-3)##=x^3-9x^2+27x-27#