Question

phan tich cac da thuc sau thanh nhan tư

a) \(x^3+5x^2+6x\)

b)\(x^2-6x+8\)

c)\(2x^2+98+28x-8y^2\)

Answer 1

a) x^3 +5x^2+6x

= x^3+2x^2+3x^2+6x

=x*(x+3)*(x+2)

b) x^2-6x+8

= x^2-2x-4x+8

=(x-2)*(x-4)

c)2x^2+98+28x-8y^2

=2(x^2+14x+49-4y^2)

=2*[(x+7)^2-4y^2]

2*(x-7-2y)*(x-7+2y)

Answer 2

a) x² + 2x² + 3x² + 6x

= x( x+2 ) + 3( x+2 )

=(x+3)(x+2)

b) x² - 2x - 4x + 8

=x(x-2)-4(x-2)

=(x-4)(x-2)

c) 

Answer 3

a) x³+5x²+6x

= x³+2x²+3x²+6x

= (x³+2x²)+(3x²+6x)

= x²(x+2)+3x(x+2)

= (x²+3x)(x+2)

= x(x+3)(x+2)

b) x²-6x+8

= x²-2x-4x+8

= (x²-2x)-(4x-8)

= x(x-2)-4(x-2)

= (x-4)(x-2)

c) 2x²+98+28x+8y²

 = 2(x²+49+14x+4y²)

 = 2[(x²+14x+49)+4y²]

 = 2[(x+7)^²+4y²]

 = 2(x+7+2y)(x+7-2y)