Solve LaTeX:  \displaystyle x^{2} + 71\geq 18 x - 1

Getting zero on the right hand side and factoring gives LaTeX:  \displaystyle x^{2} - 18 x + 72=0\iff \left(x - 12\right) \left(x - 6\right)=0 . This gives the critical numbers as LaTeX:  \displaystyle x=12 and LaTeX:  \displaystyle x=6 .

Checking the sign in each region gives the solution LaTeX:  \displaystyle (-\infty, 6 ] \cup [ 12 ,\infty) .