Question

八年级数学因式分解..

1. x^4-46x^2+25
2. x^3+5x^2+3x-9
3. x^4+4
拜托各位了，谢谢

Answer 1

1.
x^4-46x^2+25
=(x^4-10x^2+25)-36x^2
=(x^2-5)^2-(6x)^2
=(x^2+6x-5)(x^2-6x-5)
=(x^2+6x-5)(x-5)(x-1)

2.
x^3+5x^2+3x-9
=x^2(x+3)+2x^2+3x-9
=x^2(x+3)+(2x-3)(x+3)
=(x+3)(x^2+2x-3)
=(x+3)(x-1)(x+3)
=(x+3)^2(x-1)

3.
x^4+4
=(x^2)^2+2^2+2*2*x^2-4x^2
=(x^2+2)^2-4x^2
=(x^2+2)^2-(2x)^2
=(x^2+2x+2)(x^2+2-2x)

Answer 2

1.x^4-46x^2+25
=(x^4-10x^2+25)-36x^2
=(x^2-5)^2-(6x)^2
=(x^2+6x-5)(x^2-6x-5)
=(x^2+6x-5)(x-5)(x-1)

2..
x^3+5x^2+3x-9
=x^2(x+3)+2x^2+3x-9
=x^2(x+3)+(2x-3)(x+3)
=(x+3)(x^2+2x-3)
=(x+3)(x-1)(x+3)
=(x+3)^2(x-1)

3.
x^4+4
=(x^2)^2+2^2+2*2*x^2-4x^2
=(x^2+2)^2-4x^2
=(x^2+2)^2-(2x)^2
=(x^2+2x+2)(x^2+2-2x)

Answer 3

1. (x^2+6x-5)(x^2-6x-5)
2. (x-1)(x+3)^2
3. (x^2+2x+2)(x^2-2x+2)

Answer 4

这是八年级的啊。。我六年级就学了，本人升初一，，但是还没弄懂= =

Answer 5

123456