Chapter 2 - Linear and Quadratic Functions - Section 2.3 Quadratic Functions and Their Zeros - 2.3 Assess Your Understanding - Page 146: 11

Zeros: $0,9$ $x$-intercepts: $0,9$

To find the zeros of a function $f$, solve the equation $f(x)=0$ The zeros of the function are also the $x-$intercepts. $$x^2-9x=0$$ Taking $x$ as a common factor: $$x(x-9)=0$$ Use the Zero-Product Property by equating each factor to zero, then solve each equation to obtain: \begin{align*} x&=0 &\text{ or }& &x-9=0\\ x&=0 &\text{ or }& &x=9\\ \end{align*}