Question 137·Easy·Algebra

In the point $(0,4)$, what does the $0$ for $x$ tell you about this point's location on the graph? How does that help you find $b$ in $y=mx+b$?

Once you have the equation of the line, substitute $x=2$ into it and carefully simplify the resulting expression to find $y$.

In Desmos, type the equation of the line using the given information: y = -3x + 4. This uses the slope $-3$ and the $y$-intercept $4$ from the point $(0,4)$.

Click on the wrench icon and add a table for the equation, or click directly on the graph and use the trace feature. In the table, enter $2$ in the $x$-column and read off the corresponding $y$-value; that $y$-value is the solution.

Use slope-intercept form, $y=mx+b$, where $m$ is the slope and $b$ is the $y$-intercept.

• The slope is given as $-3$, so $m=-3$.
• The point $(0,4)$ lies on the line. When $x=0$, the $y$-value is the $y$-intercept, so $b=4$.

Therefore, the equation of the line is $y=-3x+4$.

You are asked for the value of $y$ when $x=2$.

Use the equation $y=-3x+4$ and plug in $x=2$:

Now simplify this expression step by step.

Continue simplifying:

So, when $x=2$, the value of $y$ on this line is $-2$.