Question

Find the coefficient of in the product of ( − 1)(1 − 2).

Answer 1

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⇒(1+2a)^4$$

(a)+ 5C² 23(a)²−5C³ 22a³+ 5C⁴2a⁴^5 - C^5 a^5

⇒32−80a+80a³ +10a⁴−a^5

∴ Coefficient of a⁴ is ⇒1×10a⁴+(8a)(80a³)+32a³ (−80a)+16a⁴ (32)

⇒10a⁴ + 640a⁴ −2560a⁴ + 512a⁴

⇒−1.398x⁴.