Question

If a2 + 1/a2 = 47, and a not equal to 0, then a + 1/a =

Answer 1

$x {}^{2} + 1 \div x {}^{2} = 47 \\ \\ (x + 1 \div x) { }^{2} - 2x \times 1 \div x = 47 \\ x + 1 \div x = \sqrt{49} = 7$
here is your answer

Answer 2

a2 + 1/a2 = (a+ 1/a )^2    -2*a* 1/a

from this relation we can get ( a +  1/a )= 7