Question

Factorise the following
$2x - 32 {x}^5 \\ 81 {x}^4 - 121 {x}^{2}$
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Answer 1

a) 2x - 32x⁵

• 2x(1 - 16x⁴)
• Using a² - b² = (a - b)(a + b)
• 2 x(1 - 4x²) × (1 + 4x²)
• Using a² - b² = (a - b)(a + b)
• 2x (1 - 2x) × (1 + 2x) × (1 + 4x²)

b) 81x⁴ - 121x²

• x²(81x² - 121)
• Using a² - b² = (a - b)(a + b)
• x²(9x - 11) × (9x + 11)

Answer:-

• a) 2x (1 - 2x) × (1 + 2x) × (1 + 4x²)
• b) x²(9x - 11) × (9x + 11)