Let x be the unknown number. Its reciprocal is 1/x.
x + 1/x = 29/10
Multiply both sides by 10x to get rid of the denominators:
10x2 + 10 = 29x
10x2 - 29x + 10 = 0
Solve for x by factoring (it does factor) or by using the quadratic formula. You'll get two answers which are reciprocals of one another.