Question

question #5 determine which of the following numbers is not a root of f(x)=x^4 - 6x^3 - 16x^2 + 150x - 225. 3 -3 -5 5

Explanation:

Step1: Substitute x = 3

$f(3)=3^{4}-6\times3^{3}-16\times3^{2}+150\times3 - 225=81-162 - 144+450-225 = 0$

Step2: Substitute x = - 3

$f(-3)=(-3)^{4}-6\times(-3)^{3}-16\times(-3)^{2}+150\times(-3)-225=81 + 162-144-450-225=-576
eq0$

Step3: Substitute x = - 5

$f(-5)=(-5)^{4}-6\times(-5)^{3}-16\times(-5)^{2}+150\times(-5)-225=625+750 - 400-750-225 = 0$

Step4: Substitute x = 5

$f(5)=5^{4}-6\times5^{3}-16\times5^{2}+150\times5-225=625-750-400 + 750-225 = 0$

Answer:

B. - 3