Question

a) x² – 4x + 3;                     b) x² + 5x + 4;

c) x² – x – 6;                        d) x⁴ + 4

Answer 1

a) \(x^2-4x+3=\left(x^2-4x+4\right)-1=\left(x-2\right)^2-1=\left(x-2-1\right)\left(x-2+1\right)\)b) \(x^2+5x+4=\left(x^2+4x+4\right)+x=\left(x+2\right)^2+x\)

c) \(x^2-x-6=\left(x^2-x\right)-6=x\left(x-1\right)-6\)

d) Câu này hình như sai r

Answer 2

a, x²-4x+3=x²-x-3x+3=x(x-1)-3(x-1)=(x-3)(x-1)

b, x²+5x+4=x²+x+4x+4=x(x+1)+4(x+1)=(x+4)(x+1)

c, x²-x-6=x²-3x+2x-6=x(x-3)+2(x-3)=(x+2)(x-3)

d, x⁴+4=x⁴+4x²+4-4x²=(x²+2)²-(2x)²=(x²+2-2x)(x²+2+2x)