[College Maths] Quadratic Equation

Need to solve this question by completing the square.

5x^2 +7x+1=0

I end up with this:

10x+7 = sqrt(29/100); 10x = sqrt(29)/10 - 7; x = sqrt(29)/100 -7/10;

According to Wolfram Alpha, the answer should be

x = sqrt(29)/10 - 7/10