Question

What are the x and y-intercepts for this function? desmos to help you identify them. 3x + 9y = 9

Answer 1

We have the expression

`3x+9y=9`

We can find the intercepts using the equation, and then check them graphically.

The y-intercept happens when x=0, because that is the definition of the y-axis.

Then, replacing x with 0 in the equation, gives us the value of the y-intercept:

`\begin{gathered} 3\cdot0+9y=9 \\ y=(9)/(9)=1 \end{gathered}`

The y-intercept is y=1.

For the x-intercept, we have y=0. We repeat the procedure and get:

`\begin{gathered} 3x+9\cdot0=9 \\ x=(9)/(3)=3 \end{gathered}`

The x-intercept is x=3.

We can check it with the graph:

We have there the x and y intercepts (x=3 and y=1).