How do you use synthetic division to show that x=1/2 is a zero of 2x^3-15x^2+27x-10=02x315x2+27x10=0?

1 Answer
Jul 12, 2018

Please see the explanation below

Explanation:

Let's perform the synthetic division

Divide by 1/212

color(white)(aaaa)aaaa1/212|color(white)(aaaa)aaaa22color(white)(aaaa)aaaa-1515color(white)(aaaaaa)aaaaaa2727color(white)(aaaaaa)aaaaaa-1010

color(white)(aaaaaa)aaaaaa|color(white)(aaaa)aaaacolor(white)(aaaaaaa)aaaaaaa11color(white)(aaaaa)aaaaa-77color(white)(aaaaaaaa)aaaaaaaa1010

color(white)(aaaaaaaaa)aaaaaaaaa_________________________________________________________##

color(white)(aaaaaa)aaaaaa|color(white)(aaaa)aaaa22color(white)(aaaa)aaaa-1414color(white)(aaaaaa)aaaaaa2020color(white)(aaaaaaaa)aaaaaaaacolor(red)(0)0

The remainder is =(0)=(0) and the quotient is =(2x^2-14x+20)=(2x214x+20)

As the remainder =0=0, x=1/2x=12 is a root of 2x^3-15x^2+27x-102x315x2+27x10

2x^3-15x^2+27x-10=(2x^2-14x+20)(x-1/2)2x315x2+27x10=(2x214x+20)(x12)