How do you solve the inequality 18x-x^2<=81?

Nov 17, 2016

The answer is $x \in \mathbb{R}$

Explanation:

Let's rewrite the equation $18 x - {x}^{2} \le 81$

As, ${x}^{2} - 18 x + 81 \ge 0$

Factorising,

${\left(x - 9\right)}^{2} \ge 0$

The solution is $x \in \mathbb{R}$

graph{x^2-18x+81 [-10, 10, -5, 5]}