Question

The function in the form f(x)=2/5x-5 is graphed below. What is the value of x when f(x)=-9?

Answer 1

`\begin{gathered} f(x)=(2)/(5)x-5 \\ \text{Now, f(x)=-9 in the above equation.} \\ -9=(2)/(5)x-5 \\ -9+5=(2)/(5)x \\ -4=(2)/(5)x \\ x=-10 \end{gathered}`