Question

factorise:
click above​

Answer 1

${a}^{4} - 11 {a}^{2} + 10 \\ {a}^{4} - {a}^{2} - 10 {a}^{2} + 10 \\ {a}^{2} ( {a}^{2} - 1) - 10( {a}^{2} - 1) \\ ( {a}^{2} - 1)( {a}^{2} - 10) \\ (a - 1)(a + 1)( {a}^{2} - 10)$

Answer 2

Solution :-

a⁴ - 11a² + 10

♦ In order to to solve above's equation we need to assign a variable value to a²

Let a² be equal to t

♦ Now equation

→ t² - 11t + 10

→t² - 10t -t + 10

→ t( t - 10) -1(t - 10)

→ (t - 10) (t - 1)

♦ Now replace t = x²

→ (x² - 10) (x² - 1)

♦ So roots

x² = 10, 1

x = ±√10 and ± 1