Vì \(x=99\Rightarrow98=x-1\)

Thay \(98=x+1\)vào biểu thức A , ta có :

\(A=x^7-\left(x-1\right)x^6-\left(x-1\right)x^5-\left(x-1\right)x^4-\left(x-1\right)x^3-\left(x-1\right)x^2-\left(x-1\right)x+1\)

\(\Rightarrow A=x^7-x^7+x^6-x^6+x^5-x^5+x^4-x^4+x^3-x^3+x^2-x^2+x+1\)

\(\Rightarrow A=x+1=99+1=100\)

Tại x = 99

1

Đề sai

=x^8+2x^4+1-100x^4

=(x^4+1)^2-100x^4

=(x^4-10x^2+1)(x^4+10x^2+1)

=x^8+2x^4+1+96x^4

=(x^4+1)^2+96x^4

=(x^4+8x^2+1)^2-16x^2(x^2-1)^2

=(x^4+4x^3+8x^2-4x+1)(x^4-4x^3+8x^2+4x+1)

1,2 hay 1 x 2

x⁸ + 98x⁴ + 1

= (x⁸ + 2x⁴ + 1 ) + 96x⁴
= (x⁴ + 1)² + 16x²(x4 + 1) + 64x⁴ - 16x²(x⁴ + 1) + 32x⁴
= (x⁴ + 1 + 8x²)² – 16x²(x⁴ + 1 – 2x²) = (x⁴ + 8x² + 1)² - 16x²(x² – 1)²
= (x⁴ + 8x² + 1)² - (4x³ – 4x)²
= (x⁴ + 4x³ + 8x² – 4x + 1)(x⁴ - 4x³ + 8x² + 4x + 1)