What is the answer to (5x+1) (x+2) = - 1

Expand it so the expression would equal

5x^2+11x+2=-1

move the negative one over by adding one to both sides

5x^2+11x+3=0

then do the quadratic formula

x=-b + / - (√ (b^2-4ac)) / 2a

where b = 11 a=5 and c=3