hello:) anyone able to explain how to solve the equestrian for part (d) ? Thank youu

Answer:see explanationStep-by-step explanation:Given4[tex]a^{4}[/tex] - 5a² + 1 = 0Use the substitution u = a², then equation is4u²  - 5u + 1 = 0Consider the product of the coefficient of the u² term and the constant termproduct = 4 × 1 = 4 and sum = - 5The factors are - 4 and - 1Use these factors to split the u- term4u² - 4u - u + 1 = 0 ( factor the first/second and third/fourth terms )4u(u - 1) - 1(u - 1) = 0 ← factor out (u - 1) from each term(u - 1)(4u - 1) = 0Equate each factor to zero and solve for uu - 1 = 0 ⇒ u = 14u - 1 = 0 ⇒ 4u = 1 ⇒ u = [tex]\frac{1}{4}[/tex]Convert u back into terms of a, that isa² = 1 ⇒ a = ± 1a² = [tex]\frac{1}{4}[/tex] ⇒ a = ± [tex]\frac{1}{2}[/tex]Solutions are a = ± 1 , a = ± [tex]\frac{1}{2}[/tex]