Question

Using factor theorem, factorise x⁴-x³-7x²+x+6

Answer 1

Answer:

Add and subtract the second term to the expression and factor by grouping .

(x-1)(x+1)(x-3)(x+2)

Answer 2

Answer:

(x-1)(x-3)(x+1)(x+2)

Step-by-step explanation:

x⁴-x³-7x²+x+6=

x⁴-x³-x²+x -6x²+6=

x³(x-1)-x(x-1)-6(x²-1)=

x³(x-1)-x(x-1)-6(x-1)(x+1)=

(x-1)(x³-x-6x-6)=

(x-1)(x³-3x²+3x²-9x+2x-6)=

(x-1)(x-3)(x²+3x+2)=

(x-1)(x-3)(x²+x+2x+2)=

(x-1)(x-3)(x+1)(x+2)