Question

factorise X³+11x²+4x-60​

Answer 1

Answer:

15x6-60..................

Answer 2

Factor Theorem

A polynomial $f(x)$ has $(x-a)$ as a factor if and only if $f(a)=0$.

Let $f(x)=x^3+11x^2+4x-60$.

• $f(2)=0$
• $f(-3)=0$
• $f(-10)=0$

∴ $f(x)=(x-2)(x+3)(x+10)$

When it is too hard to find $f(a)$, use synthetic division or idenities.

You can learn them on youtube or wikipedia.

(It's not that hard and is useful in many math question.)

(+ top 10 identities you must know)