# How do you graph -3x+7y=21?

Dec 8, 2017

See below...

#### Explanation:

Make it into a y= equation first.

so

$- 3 x + 3 x + 7 y = 21 + 3 x$

$\frac{7 y}{7} = \frac{3 x + 21}{7}$

$y = \frac{3 x}{7} + 3$

From this equation, we can see that this line would have a y intersection at 3. So label the point at (0,3)

We also know that the coefficient before the x represents the slope. So slope is 3/7. Slope is also $\frac{r i s e}{r u n}$. (From the points, you rise 3 - since its positive - and run 7 times on the grid - to the right since it’s positive.)

Since we found point (0,3) you can add 3 on the y coordinate, and 7 on the x coordinate to find other points. Then taking those points, you can draw the line to your graph.

Your graph should look something like this