Question

Expansion method need the last answer only​

Answer 1

Answer:

a-1/a=7

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

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

51=a^2+1/a^2

(a+1/a)^2 =a^2 +1/a^2+2

(a+1/a)^2=51+2=53

a+1/a=53^1/2