Question

2(a²+1/a²)-(a-1/a)-7 factorise

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Answer 1

Answer:

(a-1/a+1)(2a-2/a-3)

Step-by-step explanation:

Lets a-1/a=x

x^2 = a^2+1/a^2-2*a*1/a

x^2=a^2+1/a^2-2

therefore a^2+1/a^2 = x^2+2

2(a^2+1/a^2)-(a-1/a)-7

= 2(x^2+2)-x-7

= 2x^2+4-x-7

= 2x^2-x-3

= 2x^2+2x-3x-3

= 2x(x+1)-3(x+1)

=(x+1)(2x-3)

replacing x with a-1/a

(a-1/a+1)(2a-2/a-3)